Worn syncro on M5 (e39)

[rnjk4982]

At a track day the clutch on my friends M5 let go (no shock there). The mechanic who was there had tried to start it and engage it into 2nd and 4th gears (lots and lots of grinding and crunching) to drive it to the hangar. He really was trying to force it into gear....heavily!! My question is this. A new cltuch has been fitted and there is a crunch only when you go into 4th gear. Is this anything to do with the clutch going on the track, or more likely from the abuse from the mechanic (i use that term lightly) that has worn down the 4th gear syncro??

Nb.....it's a sealed Getrag box and so no spares available. BMW owners club told me to buy a new box (£5500!!)