I am referring to the bar scene where Walt asks just to be given access to Fring and Walt would do the actual shooting (or whatever). I initially thought Mike was trying to show Walt just how dangerous it was to even consider it or at least Mike sure did not want to be involved with something so dangerous and resent Walt trying to involve him.
But I also saw in other episodes (some in Better Call Saul) that Mike is a man of his word, gives money back when he did not have to (as when he got Tuco out of jail and refunded Nacho), and Fring has helped him in major ways -- could it be that Mike was genuinely loyal to Fring and Walt was lucky the Mike did not tell Fring what Walt said. (I assume he did not, he does not seem like a tattler.)