If illegal contact causes a violation the contact must be penalized... no matter what the player was "trying" to do.
Say the same play happened near a sideline & the bump caused A1 to step on the line. You can't go no-call there & if you call the OOB I'm sure As coach wil let you know that his player didn't step out on his own will.
What came first the chicken (bump) or egg (violation)?

It seems as though you let what you think they are "trying to do" affect your decisions.

Unless, it's a end of game situation I don't think players are ever trying to foul.