411A,
We know about the birdstrikes at higher speeds, although a good ole´ Heathrow canada goose would also do some pretty extensive damage at 250kts, if hitting the wrong spot.
But does it then mean, that you´ll never ever fly more than 250 below FL100?
It´s not so much to do with catching up on lost time, this was, one more time, an ATC request!