Magic doesn't appear to think in terms of natural laws (insofar as it can be said to think,) so forgetting to apply Newtonian physics in a particular situation doesn't sound like something the remembrall should mark as a major lapse of memory.

Regardless of what magic thinks the laws of physics are, it ought to notice how important they seem to Harry. However, I still doubt that they're important enough to Harry as all that (although the writing in Ch 60 may suggest otherwise).