Easy tronic problem Vauxhall corsa 52 plate 77k miles?

Hello
Saturday started car would not go into reverse. Turned off engine, tried to re-start and the F light came on and car would not turn over or anything. Breakdown came and disconnected the battery hoping to reset and worked for 1.5 miles longer than acceleration died and it came to standstill. Breakdown came back and said sounds like gearbox problem (possible overheating clutch) and towed to local dealer who will be looking at later. Any idea what this could be, would I need a new gear box ? If so as at local dealer (masterfit) take would be expensive ?
Thanks