Brad, what have you done.
There is a serious point that is being missed, take Pre78 as an example.
The base bike is now 36+ years old. In those 30 odd years suspension technology has jumped ahead 10 fold (or more) yet outwardly the bike looks just like it did back in the day. Engine tuning has also followed and no doubt the HP and torque is up on what they were able to achieve back in the day. We fit up the latest stainless steel spokes to Excell rims that shares duties with people like Dungey, Reed & Vilopoto yet we leave the shitty cast alloy or sometimes magnesium hubs that have done 30 plus years of work on the bike. We then bolt all this bling and HP into a frame that we have no idea of what condition it's in other then we blasted it and gave it a powder coat.
As much as the technology has moved forward so have the bag of skills that riders use. Seat bouncing to clear jumps, scrubbing to shed speed on the face of a jump, panicking revving to bring a front end up mid flight, braking mid flight to drop the nose, etc are now common place.
I have watched young "A" grade riders on the old bikes and marvel at the speed and lap times but having this terrible gut feeling that the next landing will see a frame snap in half or a hub dissenter-grate.
A one time guest or hired rider in a court of law could be seen as a employee and thus the employer could (and would be) liable for an injury claim if the equipment was deemed to be defective, more so where the employer hadn't taken the necessary steps and utilisation of available technologies to ensure the equipment was safe or fit for the intended purpose.
