False should equal None

Update(5:20pm PST, 7/2/20)
I have simplified the code and added more test cases that possibly yield a true result. I am also discovering more edge cases that I will need to take care of:
1- (SOLVED) None of the three pieces ever occupy the same exact board coordinate in the test cases. (reassigned random coordinates until the coordinates were different)

2- The black king can capture a rook if they are close and avoid the check-mate, causing the result to be False, even if the other conditions are met. Therefore, I need to add a condition to check the proximity of one or two of the rooks to the black king, and also check if the other rook still poses a check case after the first rook is captured.

3- Must account for situations where the previous move would have to have been a check condition, therefore the current board composition would not be possible.