A piece was knocked down during a blitz game I was playing a blitz game which was not part of a tournament or something but there was some bets, which were not significant at all, just to add some more spice to the game. However at some point I promote a second queen and since we didn't have spare pieces I took a rook which was already out of the game, turned it upside down so it differs from a real rook and me and my opponent agreed to use it as a queen. 

However when the time pressure came and due to the fact that when the rook is turned upside down it's not so stable in my attempt to play fast moves I accidentally knocked the rook down. When this happened I lift the rook and put it correctly on the board but this time instead of turning it upside down I put it as an ordinary rook. I think it worth to mention that I didn't press the clock until I thought everything was fixed. However my opponent claimed that because of the fact that I knocked down a piece and also that I put it incorrectly afterwards the game should not count (he was losing at this point) and refused to accept defeat.

From my perspective the things that I would like to know are - is there such a rule that said :


If you knock down a piece the opponent has the right to invalidate the game
If you put a piece incorrectly (as mentioned above the rook was used upside down, but after I knocked it down I pick it up and put it as an ordinary rook) the opponent has the right to invalidate the game
Based on the facts that I described is there something that can justify invalidating the game?
When you placed an upside down rook on the board instead of a queen you made an illegal move. In blitz the first illegal move losses the game. You lost. What happened afterwards is irrelevant.

There are differences between blitz and standard chess (longer time control). In standard chess you are allowed one illegal move but the punishment is your opponent gets an extra 2 minutes on the clock. The second illegal move loses.

Actually the position in blitz is more complicated than I said above. If an arbiter sees your illegal move he will stop the game and forfeit you. If the arbiter doesn't see then it depends what your opponent does. If he claims the game then you lost. If he plays on then he accepts the illegal move and the game continues. 

The problem is that your upside down rook is not a queen, it is an upside down rook. Every time you move it like a bishop (which the queen is allowed to do) you make an illegal move. If an arbiter sees you move an upside down rook like a bishop he will forfeit you the game. Your opponent can also claim the game for an illegal move every time you do this.

Your opponent cannot claim the game because you knocked pieces over. If you correct the position on your own time that is OK. If you already pressed the clock your opponent would be entitled to start your clock while you pick up and replace the pieces. If you continually do this the arbiter can give you a time penalty by giving your opponent an extra minute on the clock and then if you do it again after that he may forfeit you.