He might notice... well, a little shadow. Clark's not a threat of any kind, so setting off his spider-sense is really a question of sensitivity, but he's watching. Learning, honestly. This guy had a neat costume (red! he liked red. and blue! those were his two favorite colors) and he seemed to have the whole thing down pat. Stopping robbers, saving people... it's like he knows what he's doing all the time.

Clark doesn't want to ge tin the way, so, flying carefully, he follows a decent distance off to keep watching.