No. It's a $10 toy phone that the production gave to him like a week or two ago to LARP him taking calls from his employers (aka imaginary people). I don't know what kind of bond he managed to form with that thing, but definitely seems like a huge overreaction since there was $50k on the line.
But was it a predictable reaction from Jimmy?
Jimmy went ballistic earlier when Jet ordered his stuff to be thrown down the stairs.
Jet gaslit Jimmy into thinking Abby had a mission to mess with him.
Sam was tailing Jimmy after that throughout the house for an hour, so he could stop him if Jimmy went crazy.
Jimmy calmed down.
Then someone ruined his hoarder-man ashtray (Jimmy was very attached to this one). Most people expected him to flip out at this point, but he didn't.
Nobody was keeping an eye on Jimmy or telling the "Actress" with the mission to mess with Jimmy to calm down for the day.
Production made him believe all the incidents involving someone messing with his belongings were done by Abby.
I don't know why Jet thinks it's a good idea to get skinny women to anger the schizoid guy with the incredibly bad temperament without having complete control of the situation.
I believe Jet observed the engagement and TTS resulting from Jimmy's reaction, and being a sponge-brained fool, he thought he could let the skinny girls continue messing with him without needing to pay attention.
Good job jeting it up and sacrificing your last free content creating guy for a few more TTS for the day, Jet.