'If a single engine turbine is over torqued, where is the damage in the drive train likely to occur and which components most likely effected first ? Also, which maneuvers are most likely to lead to OT. Not a type specific question but more of a trawling for info one.'
On the off chance you mean a single engine on a twin engined helicopter, its possible to overtorque the one engine without overtorqing the transmission system, saying this with the Bell 212 in mind.
If my memory serves me right this is true to the first level of overtorque inspections required at 106% (without books at hand to refer to). At 112% overtorque a lot of bits will need sending away for overhaul and inspection.
A big problem is when someone sees what is happening, maybe with eyes locked on TOTs who can truly say how long it was on over torque and what the peak was, time seems to 'telescope' in times of instant anxiety.
All the info for a decision will be in the maintenance books for both airframe and engines inspections.