two flags

[c it first]

A's ball 2nd and five at their 40 yard line. A 22, who has a wide open field, catches a legal forward pass at the 50 yardline. When he is at B's 10 yard line, A 34 blindsides B 76 at B's 30 yard line. I am the umpire trailing the play. I flag A 34. My flag doesn't hit the ground and B 76 retaliates and hits A 34 with a block that knocks him back a few yards. My second flag is in the air and I am yelling for them to stop, which they do. Both realize they have been flagged and trot away from each other.
My thought is offsetting penalties, replay the down. I then thought maybe not. I report to the white hat that I have unsportsmanlike conduct- unnecessary roughness on both players. I asked if we replay the down or mark off both penalities from the spot of the foul which would give A 1st and 10 at B's 30. The WH awards A a TD . He ruled the ball was in the EZ before the fouls, therefore the ball is dead and the penalties offset. Since the UC was initiated by A ,I thought this unfair. Did the WH get it right? This is 9th grade ball , nfhs rules.