There's a handful of others who took the challenge and bested the times in various models, that's merely one example. And bear in mind, Gav hadn't driven that track before that day either - IIRC, 8 laps total, that's his 7th.
Welcome to the world of the 2ZZ powered Lotus. The gearbox is crap and the clutch is horrible - it's one of the many "add lightness" features.
Point stands, however, that they're hardly driving gods.
3 things.
1. your only example is flawed. Without other examples, we only have your word of "trust me they beat him". Hell, you don't even have timing results for your Lotus example - I had to count the seconds on the video to get a rough estimate. I have no doubt that plenty of Stig's time can be improved upon. But I very much doubt that any of your drivers are going to be setting vastly faster (1 or more seconds) lap times than he did in the same conditions.
2. a bad transmission/clutch is no excuse not to rev match, which is the most basic driving technique I can imagine. "Gav" is a driving idiot who hurts his car, which explains why he was only able to equal (roughly) Stig's wet time. And without knowing the car, the track or the tires, neither you nor I can say how much slower the wet time is than the ideal dry time. I've driven an F2000 in similar conditions (light drizzle, fairly moist track) with full rain tires and even the best driver during the session was 15 seconds slower than the ideal dry time. With semi-slicks in the same conditions, I would imagine the Lotus lost even more traction. The track plays a part too. Different surfaces react to water very differently. In fact one inconveniently placed puddle on the exit of turn 4 at Mazda Raceway was enough to add a full second to my ideal dry lap time (even though that was my fastest session all weekend, my PB is 1 sec faster). I'll even provide timing results because I like evidence.
Drizzle results
Dry results with puddle
Ideal dry results from the fastest group
For the record we use the same BFG Sport (rain) tires for dry and wet.
tl/dr, water negates any comparison to a dry time.
3. you have no standing point at the moment, except that Clarkson sometimes doesn't drive the car for the camera. Stig (Ben Collins) is not the fastest race car driver on the planet, actually he's probably not in the upper half, but that doesn't prevent him from setting a hero lap or two in a road car. He bested most of the F1 drivers in the hotlap challenge. There are plenty of race car drivers capable of completely smashing track records, but utterly incapable of winning races or championships. Driving road cars is also a different skill than race cars. Some people are better at one or the other, some at both, some at neither.
We all know that "they" ( I assume you mean all the personalities on Top Gear) are not the best drivers on the planet. MY point is that even a novice driver isn't as slow as Jeremy supposedly was at Mazda Raceway in the NSX, much less an automotive scribe of many decades.
Enough of this nonsense. I don't suppose anyone's had any goes at beating one of the Test Track lap board times?