First off... there are 12 defensive positions, even more defensive players due to rotation and such. There are on average 55-60 defensive plays during a game... That is less than 0.8 players making a mistake per series. That is not unreasonable by any stretch. Factor in the severity (or lack thereof) of those transgressions and it is not as bad as you make it seem....
Alternatively... it shows an impressive amount of diligence and meticulousness they do in film break down to catch all those errors...
******* GO BLUE BOMBERS!!!!!!!!!!