When Miguel walked into the bank and talked to Rath he completely exposed himself. How could he still proceed with the hit - wouldn't he have known that Rath was on to him and knew exactly where he would be (on the top of the hotel)?
Regards,
Rath knew Bain was waiting for him and Bain knew that Rath knew. It was all part of the game. Besides, Bain wanted Rath out of the way so he could be number one is his own mind. Bain was pretty ego-driven.
When I said I wanted to be a comedian, they all laughed at me. Well, they're not laughing now!
Even so, in the America's, banks always have just one entrance / exit, due to safety issues. While Rath is more or less anonymous down at the bank, he can not just say or tell the banker a hitman is outside the bank, because police would come, investigate everything, including Rath.
So really he has just one option: enter the bank for purposes of financial nature, the deal goes down that day... Bain has him on the grain, the only thing he has to do is be there with the rifle, whilst Rath leaves the bank. And Rath simply can't stay, the bank was already closing up. It was the end of the day.
HE HAS TO leave the bank at around the moment he does.
And by the way. Bain already considered Rath knowing where he was. As a matter of fact, he was sure of it. It's all part of Bain's plan. While he plans to kill Rath, he still is his number one fan. Which means he wants to work the plan exactly like Nicolai and Rath did it 15 years back.
"Bless me, Father, for I have just killed quite a few men."