Hmm. Interesting. Are these fairly easy to replace? I might have a go myself as you can access those from under the car...

I guess he thinks the problem is on the other side of the switch. The switch itself is obviously working as there are no codes and it works in all the other gears. His exact description was "Neutral/Drive switch not functioning in 5th gear. Possible detent gear change rod issue. All other gears ok".

EDIT:

PROBLEM SOLVED

I went out today and removed the neutral switch from the car. Checked that it wasn't stuck (which it wasn't) and re-installed it. Problem gone. All gears now work perfectly fine. I can only assume that they had over tightened the switch because it was a complete ball ache getting it out.

Those never come out easy. Glad you got things sorted out.