Maybe, although Tiffani never said she participated in GUTS in her legends interview.
That's assuming those interviews were valid. I'm still a bit skeptical about those.
The majority I can confirm. There are a few I cannot.
And those few are?
One thing not a lot of many people know is that I conducted the interview with Tiffani, not Jon, under the agreement that Jon and I could share it. In the end, while Jon posted the interview on his site, I never did on mine because while I trusted the e-mail to some extent, I couldn't confirm for sure its veracity. this is just a single example, although there are other times I declined to post an interview I conducted.
I'm quite confident that Mr. Borey's interview was truthful. His was the first I had, but he had the right balance of knowledge and inability to remember details that seemed right to me. I believe he was also the one who sent in a picture of an authentic Silver Snakes shirt.
I can confirm that Zac Turney was on the show, because he had posted about his experience on his website well before I spoke to him for an interview. He's also a recognized idol in show business... why would he lie about something so trivial?
I honestly don't know about Asher or Elise. I'll have to check up on them and see if I can get a confirmation.
I can't confirm the veracity of Jon's interview with Jennifer, nor Aaron's with Derrick, since I did not participate in these two.
Both interviews with Kirk Fogg are confirmed, and the one with Mr. Lupia almost certainly is. If I recall, he still had an e-mail address with Universal Studios.
In case you're wondering, for all new potential interviewees, I ask that they either supply a picture of the shirt they wore on the show, or if they don't have it still, a picture of themselves with a piece of paper reading "Legends of the Hidden Temple" and their name on it. This helps me cross-reference the screencaps from the episode and ensure that the interviewee didn't just grab a picture from Google. I imagine this should be sufficient for our needs. If you're wondering how I can confirm the shirt wasn't reproduced, it is because the reproductions' logos aren't perfect.
I hope this answers your question, because I feel like I've been typing for a while.