The assasin being captured alive complicates things for whoever ordered it.
Q1: was the killer supposed to be captured alive?
Q2: if army ordered it, wouldn't the alive killer confess?
Q2A: same question, even if Immy ordered it on himself.
Q3: maybe killer is a genuine lone wolf, possibly mentally unstable?
Q4: how many killers were there? Some sources saying 2. Crazy lone wolf story falls apart if there were 2 killer, return to questions 2 and 2A.
Occam razor analysis tells me if this was ordered, then it was botched. The 'I shot him Just because' is maybe a backup story spoonfed to the killer to tell the police if he is captured.
Weak defense though, and Punjab police 3rd degree will get the truth out fast.
Powerful parties Might try to have him declared mentally insane and destroy credibility.
If there were 2 killers then Imran was not supposed to survive. Why use 2 shooters to just send a message, or to make a politicial statement? One is enough for that.