Big cloud of steam

I'm doing my normal Sunday drive which is about 20 miles through Fort Lauderdale/Pompano Beach yesterday in my 1989 Mondial T Coupe. Things are warmed up nicely,
not too hot as its about 7pm, still about an hour of daylight left. Gauges look good right in the temperature zone. Then I see a cloud of steam behind me and the smell of
coolant. I just pulled out of Shelton Ferrari's parking lot, which is part of the weekly ritual. Any way, I coast into Red Lobster's parking lot and drive all the way to the back lot and call AAA. While waiting, I see a nice big puddle of coolant under the engine.

Mind you, I just had the major service a few months and about 500 miles ago. All the hoses were changed during the service.

Today, I try pouring some water into the expansion tank and the water with some coolant just starts draining out the bottom of the car again. I grab a flashlight and try to see if I can spot the source of the leak. After a while I see the culprit, its a hole in one of the hoses. This goes into the motor (from the rear bumper side) to the right of the gearbox and above the right drive shaft. Remember this is the T Coupe so the engine is longitudinal with the ''t'' gearbox.

My question is what causes the rupture/tear/hole in a brand new hose? Faulty hose? Possibly nicked during installation? Or could it be another issue like excess pressure? The hole was about 2 inches from the clamp so it wasn't directly near the clamp that you could say cut into the rubber.

Its in a spot where the car needs a lift to replace the hose, glad it seems to be minor but hate needing to get it towed to Tim Stanfords, have him put coolant back in etc if I can just do this at home.