In the pub the first time, Vision sees Paladin as the man commanding the operation and flies away. He saw the person responsible, like finding Osama Bin Laden, and flew away.

In the pub the second time, Paladin is the threat to Tommy. With Paladin dead, the goons have no orders. But more realistic would be for Vision to take Paladin, track Philomena, and exchange Paladin for Tommy.

Yeah the third I'll give a pass because he was damaged. But the entire situation was ridiculous. He could have phased in. The bullets and grenades weren't threatening.

The reason this was poor writing was because in the second pub scene, Vision showed off just how super genius he was by knowing exactly what Paladin would say. Yet Vision attacked like he was in a Vin Diesel movie.