Mate, simple fact is that just because Woolongdingdong describes its Super Grippy Hyper Performance Max Extreme Action 5000 tyre as a high performance tyre doesn't mean it's actually going to be any good. I'd never ever try and save money when buying tyres, especially on high performance cars. My mate used to buy remoulds for his Laguna and eventually listened to me and bought a proper set of tyres and couldn't believe the difference. The descriptions on mytyres come directly from the manufacturers and have nothing to do with mytyres, it's down to the manufacturer. Whoever is the unknown maker of the crappy tyres he bought clearly feels that the tyres perform within the company's parameters for that tyre, but they will clearly be far lower than those of a proper tyre company. Finally, this thread shouldn't have been called "Word of warming about mytyres.co.uk," but something like "word of warning about buying crap budget tyres." Next month's evo is going to have a huge test of high performance tyres from 9, no doubt well known, manufacturers, I suggest everyone has a read when it comes out.
Just wanted to add that I am sorry to hear about your friend's car but reading that he always buys budget tyres I'm amazed he hasn't had a big smash sooner. Honestly, just spend a little more and get a tyre that you can trust, worth it in the long run.