Originally posted by Don Pappo Napolitano:
...I would have gone with Michael if I was the one in that situation, I would never allow anyone to go alone if I am supposed to be in danger...
Sollozo frisked him before he went in. McClusky had frisked him in the car (he'd frisked a thousand young punks). He was 'clean'. He'd asked permission to use the bathroom per Clemenza's instructions. As far as they knew, nobody from the Corleone Family even knew where they were.
Though clearly Sollozo thought it odd that he'd have to get up to use the men's room during such an important meeting...like McClusky said, 'When you gotta go, you gotta go.'
As far as the they were concerned, there was no danger, no reason to follow Mike in.
Apple