Would definitely have to see the plays.  These blocks at the LOS in close line play are legal by NFHS rules, however the INFC has a special exception to the rule making all low blocks illegal even in line play.   It’s always possible some officials aren’t aware of all the INFC exceptions.

Also, The linemen are allowed to “grab grass” and hold their position, but not drive directly into the legs of the opponent.  It’s a tough distinction and can be a matter of interpretation and judgement.  Could have been a matter of one play was much more aggressive than the other, or different officials just saw it differently.