The 57-year-old actor is accused of punching a man who was drunkenly making noise outside his home in Whitley Bay in the early hours of 30 May 2021.
He denies causing grievous bodily harm and says he only pushed Karl Poole away in self-defence.
Prosecutor Michael Bunch claimed the actor "snapped" and "lashed out".
In his closing speech to the jury, Mr Bunch said this caused Mr Poole to fall and hit his head on the pavement, fracturing his skull.
Newcastle Crown Court heard the DCI Banks star came out of his house wearing pyjamas and a dressing gown after seeing Mr Poole and his friend Andrew Hall drinking at the bottom of his driveway at 05:30 BST.
A neighbour watching from her bedroom window told the court she saw Mr Tompkinson slap and punch Mr Poole, but the actor said he could not have done this because he was holding his phone at the time.
Mr Tompkinson, who was born in Stockton-on-Tees, had argued his profession made him less likely to assault anyone because it would be "career suicide".
Mr Bunch asked jurors: "But when we snap, do we worry about the consequences in that moment?
"Do we think about anything else other than that which has made us see red?"
The jury might think the actor's "obvious talent makes him convincing in putting across a story", the prosecutor told them.
"He is an expert in playing a part - a man tormented by a pair of drunks. He can deliver a line," he said.
Mr Bunch reminded jurors Mr Tompkinson had described the men's behaviour as "disgraceful" and "pure self-indulgence by grown men who should be behaving better".
Nicholas Lumley KC, defending, said the actor was "sought out by producers because of his calmness".
He asked jurors: "Why would he risk throwing away that hard-earned reputation?"
Jurors heard Mr Poole and Mr Hall had been drinking since midnight and had passed Mr Tompkinson's home in North Tyneside on the walk back from the beach.
The actor, who was living with his partner and her seven-year-old son, said he had heard "strange noises" and went out to challenge the two "heavily-intoxicated" men, one of whom was wearing just underpants.
He called police after seeing the pair repeatedly fall and try to stand up while drinking from a bottle of Jägermeister, the court heard.
The actor told the court the two men "took great objection" to him complaining and had started to move towards him.
He said he put his hand out to stop Mr Poole coming any further and made contact with his face, but told jurors it "wasn't enough to knock a sober man off his feet".
The jury has been sent out to consider its verdict.