BTW FOX, i'd have ran it a second time. I'd have thought the same as you, hmmm 07 BMW failing emissions, thats strange, lets give it a bit longer to warm up and try again. Either that or test drive it then try again.
And this is the crux of my dissapointment. I'm glad you've got a bit of common sense! It seemed none of this happened, they just went 'computer say no' and issued a fail.
Depending on the customers level of knowledge this could have been a disaster - what if the owner of the now failed car had said 'oh, can you replace my cats then please?'
£1k for nothing!
It usually sayes on the VT40 (mot check list) if the car is unsuitable for testing on brake rollers, but don't assume the tester knows that or bothers to read that. ALWAYS tell the tester when you present the car or you may find they aren't liable for any damaged caused.
.