Melbourne

Sarcastic/aggro tone not called for dude. If you google "water drops leaf scorch" or any other such combination you can get plenty more sources outside the UK including actual research into the premise. Whether scorching happens isn't because of the heat (if anything the water is likely to dry up faster at higher temperatures), it's due to the shape of the droplet forming on the leaf (and obviously assuming the water isn't high in salt or other compound).

Sure, it sometimes can be a problem on a few plants where the water sits on the leaf in full sun in a puddle long enough for that effect to happen, such as succulents.

But for the average person just wanting to water their average plants, where the process of watering is likely to leave only droplets and they have petioles down which the water can roll off? No. And between "oops I forgot to water my plants so I'll just let them desiccate even more" vs "oops I forgot to water my plants so I'd better give them SOME water now rather than let them curl up and die", I would really rather people do the second than the first.

I haven't got academic journal access any more to find the actual papers researching it. But here is a decent summary of several answers in one place. (and here you can find a long argument in the comments involving the author of that last paper from Hungary about whether hairy leaves actually do get leaf scorch more)