As with Chris and Gordy, I would have no issue with the decision that was made. A qualified technician has checked the mag plug, a TRI has decided to fly home, the engine was run for ~10 minutes before departure and (I guess) no further chip warning occurred. Especially if the chip was 'hair like', there is no issue that I can see that would warrant the helicopter being returned on a truck.
Quite honestly, you are likely to get more damage from the pounding the engine would get on the back of a truck
