佰 vs 百: inconsistency in use I saw a portion of a video course of Japanese tutorials aimed at Hong Kong Cantonese speakers, and notice that while introducing Japanese numbers, they translated the Japanese word for 600 as 六百, then straight afterwards, the word for 800 as 八佰 (with the hundreds place in 大寫).

I can't think of a reason for the inconsistency — can you?
A possible answer which accounts for the fact that the video was made in Hong Kong:

The cangjie (倉頡) code (the input method prevalent in Hong Kong) for 八佰 is HO OMA, and the code for 八百 is HO MA. A simple duplicated character would account for the error.