DRider - the only reason that they will technically 'fail' you is if you prove to be a danger to yourself or others. I find it a little odd that some of the examples on here were 'passed' (I'll use that word, as the 'pass' does get you a certificate that allows you to proceed, after all), as that's what the CBT is trying to spot - normally, they'd recommend a little more training in some of these examples, then pass you.
If it makes you feel better (I've lived in Cumbria, on the coast near Millom), this was my CBT in Kent:
- I turned up on the Saturday in the car with the radio reporting that we had the strongest winds in the last 15 years.
- The site is next to Manston airport, so it's a wide open area next to one of the longest runways in the country (it was an escape route for the Shuttle and Concorde)
- We left the site and took a short cut past the nearby farm to get to the urban areas and a petrol station, only to stop and turn around because a tree had come down over the road, bringing a power cable with it.
- After turning around, a gust of wind altered my route straight into the front of a police car arriving to mark off the danger area (luckily, both she and I knew what caused it, so no hassle from her)
- We pulled next to the forecourt to fill up and stopped because of traffic - just in time to see a thirty foot long Sainsbury's advertisement whip by in front of us like a will-o-the-whisp. It was big enough to take out all three of us.
- About 3/4 of the way through the ride, it started to rain (an understatement) and started bouncing two feet off the ground (no exaggeration). At this point my radio went 'weeeeee.....' and died. Thinking it batteries, the instructor decided to call it a day, especially as he considered us all 'passed' in any case.
- We drove back along the side of Manston, with us all leaning at 45' (again, no exaggeration) just so we wouldn't all over. it was the weirdest sight you can imagine - we all looked like we were continually turning a corner, even though the road is as straight as an arrow for a good mile.
- When we took off the radios, I upturned mine - the ding turned out to be water. About half a litre of water pouted out of the air-intake, just like I was pouring it from a jug.
If some one who at that time had had 1/2 hour on a bike can pass under those conditions (oh, what fun....), seriously, don't worry about it.