Anecdotes are useless without film to back them up.
One thing to remember, though, is that if you see someone warp, and it is truly because they have a connection issue, then they, too, are seeing everyone warp around them as well. Hardly a surefire device to gain an advantage . . .
The other thing to remember is that the planes are rendered differently as you get closer, for example when you are close enough that the chosen skin is finally displayed (old N1K changing form green to orange on your screen, for example). When I do see a warp, it is usually about D400, i.e. just about firing range, and also when the skin renders, causing a temporary increase in data traffic as his PC tries to tell my PC which skin I should be seeing. So, yes, it may seem to be an awfully convenient warp, but it has nothing to do with anything malicious.