Bengals fans...

[*rfaulk34*]

(01-11-2016, 06:38 PM)StrictlyBiz Wrote: Rule 13 Article 2

Either or both team attendants and their helpers may enter the field to attend their team during a team timeout by either team. No other non-player may come on the field without the Referee’s permission, unless he is an incoming substitute (5-2-2).

During any team timeout, all playing rules continue in force. Representatives of either team are prohibited from entering the field unless they are incoming substitutes, or team attendants or trainers entering to provide for the welfare of a player, and any game-type activities are prohibited on the Field of Play.


http://operations.nfl.com/the-rules/2015-nfl-rulebook/

You need referee's permission to be on field. Given Porter was out there for some time and in the presence of the ref's, I think that permission is implicit at that point. It's rare but not unusual for coaches to be on the field during an injury. 

There's usually not a problem because other coaches that come onto the field aren't rancid turds like Porter; whose only intent was to provoke a Bengals defender.