offsetting penalties?

[BigGref]

I had a play last night, I was on far side of the line, on the other side is a guy who does very few games below NCAA. there was a dead ball foul, close between Defense jumping in and Offense jumping at the same time, it was on his side and it was again very close. I go in to help add anything I could , the final descision (led by the college guy) was dead ball offsetting False start on O and encroachment on D. Is this possible? and has anyone else had this?