Although any alibi that places Harry with Quirrell is liable to increase Dumbledore’s suspicions instead of reducing them, no matter how airtight it seems.
This would provide an opportunity to have Harry explain conservation of expected evidence to Dumbledore, which is very slight evidence that it’s going to happen (and would make a fun scene, in any case).
This would provide an opportunity to have Harry explain conservation of expected evidence to Dumbledore, which is very slight evidence that it’s going to happen (and would make a fun scene, in any case).