Only listened to the game, so this is speculation rather than an "eye-witness account," but it sounded like what the Prep D-line was doing near the goal line was deliberately jumping the count either to increase the chance of a stop or, more likely, to incur the 6-12 inch half-the-distance penalty in order to induce LaSalle to jump next time and thus get a 5 yard penalty. It's the kind of thing Infante, who coaches with something of an edge, does quite a bit. If the intention was to injure the LaSalle players, there's no excuse.
When I was in Little League a long time ago a kid whose family had just moved from Brooklyn joined our team. His father used to sit in the stands and yell things like "The kid swings like a broken gate" when an 11-year old was batting for the other team. Our manager had to tell the father that in the Philly area parents didn't make such comments. The analogy isn't exact, but I think one could say that Infante coaches with an aggression influenced by being a New York-area guy.