Was the RV plugged into that house GFCI when the workers overloaded the plug? If so, tripping under high currents could have weakened the house GFCI.
If you're talking about overloading a plug inside the RV, that wouldn't cause a GFCI to trip later on unless there was arcing or enough heating to create a carbon trail inside the plug. I'd think this would leave visible indications of abuse on the outside of the outlet.
Try Ernie's suggestion. Turn off all of the breakers in the RV, plug in and see if the GFCI trips. If it does, the problem is in the power cord or plugs. Now turn on the main breaker followed by one circuit breaker at a time until you get a trip.
It's a long shot, but possibly the pounding by the floor installers could have pinched or caused a sharp edge to drive into an improperly run wire.
Another thing you can try is measure the resistance between the ground pin and the remaining pins on your power cord. Any resistance reading at all indicates a problem since a GFCI will trip on something like 200,000 ohms of leakage.
Make sure you do not touch the plug pins or the metal probes while measuring or you'll measure your body resistance instead of any leakage. No the RV was at another location and a 30 amp was used.