Do you guys know how fast he was going? I did not see his Speedo in the shot. Perhaps the rain and poor visibility adds to perception of "speed"?
So, how fast was he going?
IMHO, did not seem to be going all that fast. Based on dashed centerline, I'd make a guess of about 60 mph (96 kph).
Seems like he went Hydroplaning out of control? Worn out rear tire?
Maybe Diesel on the road?
Seems like he may have shut off throttle when hydroplaning started ... in an instant he was sideways, then down.
It's hard to do ... but STAYING ON THE THROTTLE IS BEST... to get through this. But if Diesel is in the mix, then it's tough.
Some roads can be dangerous in Mexico. Mostly you have to watch for CRAZY unmarked road hazards, Pedestrian traffic, Dogs, Horses and Burros. I've nearly hit ALL of them.
But some roads are EXCELLENT and SAFE ... even in the rain,.
I've ridden in the rain, at night at 80 mph. If your shield and Anti-Fog are good, then it can be done safely on the right road.
On THAT road? no, I would not go 80 mph ... but I wasn't there so I'll let the rider speak to what he felt was safe at that moment.
Bad luck, so glad he wasn't seriously hurt. That is the best news of all. Bikes can be fixed/replaced, bodies ...? not so much!
Carry on!
PS: You're lucky Policia did not show up. If they did, they'd impound your bike, then charge you for "damaging the road" and huge storage/impound fees as well. I am 100% serious. That is what they do in Mexico!