The H threw the flag to the 25 yard line, the R never announced a number for the fouler, the call was not announced as a dead ball foul, and the announcment was for "Unnecessary Roughness". Given all of that, I watched to see if there was any defensive player near the 25 on whom this could have been a live ball foul.
Nope. The only possible foul was on the tackler, and that clearly would have been OOB and a dead ball foul. Poor judgment call, followed by a really botched enforcement. Ouch.