Good god man, how long am I gonna have to babysit you?
Unnecessary roughness is almost NEVER called when somebody tackles a ballcarrier, unless it's after the play. I can't go through every single solitary scenario. But for those you mentioned... If a ballcarrier gets tackled illegally, the refs have specific calls for the type of hit... i.e. spearing, helmet to helmet for QBs and defenseless WRs, launching, etc. If a QB is attempting a slide, the play is dead as soon as he begins his slide, so any unnecessary roughness call would still be AFTER the play.
If a guy, not a ballcarrier, gets hit away from the play, but during the play, that's typically going to be unsportsmanlike conduct. Or say a tackler clotheslines a ballcarrier, or picks him up and violently throws him down, or something else that is blatant... the call is typically going to be unsportsmanlike conduct.
And OF COURSE they can call unsportsmanlike conduct for things happening after the play... celebration, taunting, fighting... "Unnecessary roughness" wouldn't exactly fit for excessive celebration would it?? At least I don't think the NFL's reason for penalizing Chad Johnson or TO's celebrations is because they are "too rough" on the opposing team...
Let me bottom line it for you. If unnecessary roughness is called, it's almost always for something that happened after the play. I qualify it because I've never seen it called for a legal hit on a ballcarrier during the play, though a ref somewhere, sometime, MAY have called it. Ayodele's hit was legal; typically they wouldn't call unnecessary roughness on a legal hit on a ballcarrier, unless the hit was after the play. Therefore I believe the ref thought the hit was after the play, which IMO is clearly wrong. I thought it was wrong when it happened in real time, and after watching replays I still think it was wrong.