vaishu...2 things are very clear...
that person is dead due to excessive alcohol...
mishbir never ran out of crime, abir took mishti as she is unconscious and he knows police are near so they can take care of that unconscious guy too...
Yeah that's Of course is clear
But blood coming out of forehead is also a reason na, just overdose nahi. Agar dono mein se Kuch ek hota like only overdose or only blood coming out then Wo Sirf unconscious hota but dono hua thata why he died.
He took mishti away because of the reason we know, but when police will ask he has to prove the reason and that's the main problem, sunsaan jagah pe proof kaha se milega.
He didn't knew that the person is dead when he left the scene, after hearing police siren he thought that they'll take care of him, but after visiting police station he got to know that person is dead Because of overdose of Alcohol.
He didn't expected that but ab varun is in the scene so he'll need proofs to prove his statement