The only obvious purpose would be to delay Harry, and it seems like a singularly inefficient way of doing that—I think anyone trying to predict his actions would have assigned good odds to him ignoring everyone and everything else and zooming out of there the second he thought Hermione was in trouble.
Furthermore, there are all kinds of ways trying to magically influence a professor could have backfired. The benefit doesn’t seem worth the risk.
The only obvious purpose would be to delay Harry, and it seems like a singularly inefficient way of doing that—I think anyone trying to predict his actions would have assigned good odds to him ignoring everyone and everything else and zooming out of there the second he thought Hermione was in trouble.
Furthermore, there are all kinds of ways trying to magically influence a professor could have backfired. The benefit doesn’t seem worth the risk.