Judgement in the negligence claim by Pc David Rathband's family against the shot policeman's employer Northumbria Police could be known in weeks.
He was blasted twice and left for dead by gunman Raoul Moat minutes after the maniac had phoned 999 to say he was hunting for police.
The late traffic policeman's siblings have brought a High Court claim, saying if senior officers had warned him he would not have been sat stationary in his patrol car on a prominent Newcastle roundabout above the A1.
In a closing speech at Newcastle's Moot Hall, Geoffrey Tattersall QC, for the claimant, said: "Had the warning been given, it is inevitable Constable Rathband would have been able to protect himself."
Northumbria Police said in court that Assistant Chief Constable Jo Farrell, who was silver commander for the July 2010 manhunt, had regard for the public interest and if she had rushed, another serious incident could have occurred.
John Beggs QC, for the force, said: "That's the balance Farrell had to consider in the heat of the moment."
Mr Justice Males thanked both parties and said he would reserve judgement.
It is understood it could take four to six weeks.
Pc Rathband's widow Kath was in court and declined to comment afterwards.
The claim has been brought by the officer's twin Darren and sister Debbie Essery, as executors of his will, and they have stated should it succeed, any compensation will be paid to his two children.
Pc Rathband, who started his career in Sunderland, killed himself in February 2012.