I've been doing Varsity ball for a couple of years, so I may not be the veteran that you are looking for, but here goes anyway
Hand-checking is generally pregamed: I've heard some of the crew chiefs say, "we're going to call anything that is two hands automatically", or "if they have that hand on their more than a couple of seconds we're calling it".
So while it may have been viewed as hand-checking the calling official may have decided it didn't disrupt the offensive player enough to warrant a call. At this time of year, I think some officials are trying to make only the calls that are substantial and needed. A couple of "ticky-tack' calls could put a star player on the bench and cost a team a chance for a championship.
That's a philosophical argument though.
Same with rough play: I have seen and I'm sure a lot of high school officials can agree that a lot of times, the offense is initiated a lot of contact and consequently we don't penalize the defense for the physical play. So we no call it.
Of course, without seeing the games, it's hard to say. but those are my general thoughts.