I seem to recall that the reason that Harriers weren't allowed to fly over London for fly pasts in recent years was that the risk of engine failure was too high given the chances of landing in a heavily populated area. Not helped by Harriers not gliding very well (JF feel free to comment as appropriate!) No such issues of course for Hawks.
True, but the only Hawks allowed were (and still are) the Red Arrows, presumably because the pilots' exceptional skill and judgement guarantee that they could point the thing safely into the Thames before ejecting after an engine failure. A 'standard' Hawk pilot is not trusted for this purpose!
Seem to remember that engine-related ejection from a Harrier was practically a monthly BTR for a while in the mid-late '90s (although to be fair there were a couple of pilot-induced ones, too).