Every machine has limits. These limits are clearly identified on the machine - SWL for cranes, max load at load centre for lift trucks...etc
I would assume that a tow truck has the max load that it can tow clearly marked.

In Europe, if an industrial machine is put into operation doing something it's not designed to do, the factory operator wouldn't have a leg to stand on if someone got hurt and put a claim in.

Sure - some folks use forklifts for towing, just the same as a 5T truck gets to lift 7T the odd time - doesn't make it right.

Forklift suppliers shouldn't be telling operators that they can tow.