Watch: Steelers' Marcus Allen commits dumbest penalty of the season

Some context here: with the Steelers leading 21-7 late in the third quarter, they had just sacked Carolina Panthers quarterback Sam Darnold on back-to-back plays to knock them out of field goal range and set up a fourth-and-27 as the third quarter came to a close.
 
With the two teams standing around during a TV timeout during the quarter switch, and the Panthers set to punt, Allen took it upon himself to walk over to the Panthers sideline, trash talk some players, bump a player, and then try to get into their huddle.
 
This resulted in a 15-yard personal foul penalty and an automatic first down.
 
The Panthers ended up getting a field goal on the drive.
 
That was the Steelers' second post-whistle personal foul of the game, following a taunting penalty against wide receiver Diontae Johnson.
Not the type of stuff you want to be doing when you have a 5-8 record.
Especially when you are a backup safety that only plays on special teams.