If you don't mess up live, you're not a bassist. You're a sequencer.
Off the top of my head, I've seen Danny Lohner of NIN screw up a touch, but that's only because Trent Reznor was slamming into him at the time.
Pete Steele of Type O Negative has hit some bad ones, but manages to turn them into beautiful feedback. Hell, even John Myung, who I'd classify as a "machine" hits the occasional clam.
The top story I've ever heard comes from Mike Keneally's bassist
Bryan Beller, who writes about one of his first gigs with MK back on New Year's Eve of 1993. Reading about it, however, it's more than understandable;
"...Keneally was changing forms on the fly, extending sections that I thought had no business being extended, changing his part so much as to be unrecognizableand differently every time. These guys were clearly operating at another level, and while they were as encouraging as they could be, I simply didn't know how to get there yet.
It showed in the performances. One was in a ballroomthe Catamaran, I believeand the other was in this gigantic airplane hangar that was mostly empty.
I tried my best to hang in there, but I was exposed on the simplest song: "The Car Song," of all things. The coda has a section where you groove in D minor for a certain number of bars before switching over to D major to take the song home. I was so focused on making sure that Toss didn't throw me off the beatbecause he was ****ing with the meter like crazythat I automatically switched tonalities at the same point as the recorded version. Well, I wasn't looking at or listening to Keneally, because if I had been, I'd have heard him clearly stay put in D Minor. I went to D major anyway, and wondered for nearly 20 bars why everything sounded so ****ed up. In what must have seemed like an eternity, Keneally waited for me to catch on and switch back to D minor before giving me the cue I should have been looking for all along. To make matters worse, it was the show closer.
Neither of us left that night feeling like any magic had occurred." 
Yet over 10 years later, they've worked on over 15 "projects" (full-length albums, tribute album tracks, other people's albums, etc..) so it goes to show you.
A major screw-up on your
first gig won't necessarily kill your chances at the gig. You might even make a career because/in spite of it.
