A woman's testimony was considered inadmissible in a court of law. Whose law? As an argument for the validity of the Gospels, I have heard it mentioned by multiple pastors that a woman's testimony was considered inadmissible in a court of law, so the fact that women first discovered Jesus's empty tomb (e.g. Luke 24:10) is an indicator that the Gospel writers weren't fabricating their stories. 

In reading through 2 Chronicles, however, I have been noticing a pattern in which the mothers of some of the kings have been mentioned (e.g. Jehoaddan in 2 Chron. 25:1, Naamah in 2 Chron. 12:13), and there is even a queen who reigns, Athaliah (2 Chron. 22:10), who is also mentioned in 2 Kings.

I know that certain women play major roles in Biblical events (Sarah, Esther, etc.) I'm also aware that in Judaism, a child is considered Jewish if the mother is Jewish, and I am certain that this plays a role in many of these passages, in terms of validating the lineage of various kings.  There are also cases in which no men are living in a family, and women become heirs to a family's inheritance (Num 27:2-4).

There are other parts of Scripture which have led some Christians to percieve women as "lesser" than men (e.g. 1 Tim 2:12), but the overall impression I get is that women have had very different, but equally critical roles throughout Scripture.

It seems like this argument of a woman's testimony was probably true of the Roman law, but by reading through the Bible, I'm not convinced that it was true in Jewish circles, and I wonder if the argument itself isn't a little misleading.  I think it would pertain specifically to the Roman culture, but the initial push of Christianity was meant specifically for other Jews anyway, not for gentiles.

Note:  I ask because I want to both 1) understand this argument, and 2) this aspect of Jesus's culture more accurately-- so if you have sources, please cite them.  I'm not looking to discount the authority of the Gospels:  I believe the accounts were accurate, and I'm a firm believer that all Scripture is breathed by God (2 Tim 3:16). Nor am I looking at this with an agenda (I happen to be a complementarian, but my wife is not-- God's mercy and love is way more important to me than my own views or blind rule-keeping).  Also, I am not trying to create a controversy, so please keep it civil!
Transistor I feel you. I think oftentimes the answer is not clear but many Christians take comfort in believing all of their church's teachings and their apologists' arguments are valid. When I ask questions about the premises or certain details which seem to be contradictory I am often told not that the answer isn't really known or that the answerer disagrees, but I am wrong and should read a book. In the majority of cases I suspect the person answering knows less than I do about the subject but just doesn't want to be seen admitting that something they believe might be false. Even if it is a modern doctrine. I think this is unfortunate as it has led to many religious splits and wars.

Anyway, in this case if you look at Jewish rabbinical law from the Talmud, women are generally not considered admissible witnesses in a courtroom. Here are sources:

http://en.m.wikipedia.org/wiki/Testimony_in_Jewish_law

http://www.jewishvirtuallibrary.org/jsource/judaica/ejud_0002_0021_0_21003.html -- see Women

Since the Talmud was written by the rabbis who were codifying Jewish law in the tradition of the pharisees starting a mere 100 years after Jesus, it seems likely that this was Jewish law generally at the time when Israel had its own courts.

We are talking here about court testimony, though. How men reacted to women is a related but different matter. The opinions about women as witnesses may have spilled over to the disciples - but given that Jesus freely included women among his group and they were all like a big family, I doubt that this is a criterion for embarrassment any more than other mentions of Mary Magdalene in the Biblical as well as Gnostic gospels.

http://en.m.wikipedia.org/wiki/Mary_Magdalene

Moreover another problem for the argument that the gospel writers "wouldn't have put women" as the first ones to see the tomb is the way this information is treated. Luke specifically pointsout that a bunch of women talking about the body no being there didnt make any sense:

http://biblehub.com/luke/24-11.htm

To me it is much more curious that the subsequent verses describe people talking and walking with Jesus, but not recognizing him. It is interesting what the notion of resurrection really was. These stories all have a bit of a mystical quality.

But to answer your question - yes there is a precedent to suppose that women's testimony was not usually admissible in court and this may have affected the disciples. But these werent just any women, they were the ones who were by Jesus' side when the men had fled. They were around for years and part of the family. It could have been that the disciples didn't believe because the women had trouble relaying such an event.

Consider this also: the gospels differ on what the women saw. As for the centurions who saw things, the gospels claim they were bribed by Jews to say nothing happened. Here is Matthew 27 on the events before the burial:

"51At that moment the curtain of the temple was torn in two from top to bottom. The earth shook, the rocks split 52and the tombs broke open. The bodies of many holy people who had died were raised to life. 53They came out of the tombs after Jesus’ resurrection ande went into the holy city and appeared to many people.

54When the centurion and those with him who were guarding Jesus saw the earthquake and all that had happened, they were terrified, and exclaimed, “Surely he was the Son of God!”

55Many women were there, watching from a distance. They had followed Jesus from Galilee to care for his needs. 56Among them were Mary Magdalene, Mary the mother of James and Joseph, and the mother of Zebedee’s sons."

The whole thing sounds a bit fantastical - we don't find reports of resurrected saints anywhere else. But assuming this was true, then:

1) Resurrections and coming out of tombs already occurred on a large scale so it's strange why the disciples couldnt believe it happened again.

2) The centurions were already so impressed they were convinced that Jesus was the Son of God. So it's a wonder how they were able to be bribed by Jews to say nothing happened after witnessing the empty tomb of Jesus. Why was the money that big of a deal to them at that point?

To me these are bigger questions than why women saw the empty tomb first.