It was definitely NOT a “It’s not my place to ask that question.”
Walt was in full Heisenberg mode - the baddest of the bad-asses.
He was telling Gus that he respected him as a businessman, and would never actually think that he ordered the hit on the kid.
Gus respects Walt (actually, Heisenberg) because of his talent, but lately more so because of his integrity.
Jesse, however, is a known wild card. If Jesse thought that Gus issued the hit, then it doesn’t matter if Gus did or didn’t - Jesse thinks it happened, so Walt must intervene to save Jesse’s life.
Walt was telling Gus that he protected his guy (Jesse) even if under the flimsiest of pretenses.
We know now that Walt was lying when he told Gus that Jesse was two time zones away. I figured he was, but it was nice to see that I guessed correctly.
Walt, as I said earlier, has completely made the transition to crime boss now. He is smarter than anyone else he deals with, and it is starting to show. As Walt gets colder, his decisions get smarter.
Just look at his blubbering, pleading performance in front of Mike. A total act, with the only goal to get him on the phone with Jesse.
The Walt transition is amazing - anything now to advance his agenda is OK.
If he saw himself 3 years ago he probably would be arrested and would spend the weekend in the local hoosegow!