There's an unwritten code that exists between actors working on Broadway: you do not abandon your fellow cast members and crew unless it's absolutely necessary. If an actor walks off the set of a film, he must deal with studio heads and usually it all works out one way or another. But on Broadway the show must go on, so bailing at the last minute puts everyone else in a potentially embarrassing situation.

So it's no wonder that Jeremy Piven would be going out of his way to explain himself after bailing on the play Speed-the-Plow, citing mercury poisoning as his excuse after years of eating too much fish. People Magazine reports:

From the second week of rehearsal for the revival of David Mamet's Speed-the-Plow, the Entourage star, 43, told Good Morning America, "I was losing my balance and my memory. The lights were too bright. I couldn't get enough oxygen."

After passing out in his home after work one day, he was admitted to the hospital for three days while doctors ran extensive tests, Piven says. Doctors discovered he had six times the levels of mercury found in a healthy person, which was causing his symptoms, and warned that he could have a heart attack if he overexerted himself.

"The only protein I got for 20 years was from fish," says Piven, who adds that he ate sushi at least twice a day. "I kind of thought I was doing the right thing ... As soon as I heard this, I stopped all fish whatsoever."

Piven has admitted to being embarrassed by the situation, especially given the skeptical response he got from fans, late-night hosts and colleagues alike. Speed-the-Plow playwright David Mamet joked that Piven was leaving show business to "pursue a career as a thermometer."

But Piven, who hasn't eaten fish in five months, says he has no hard feelings: "[Mamet] is a brilliant playwright and that's a funny line."

Even if Piven's story of mercury poisoning may be true, it's not exactly tactful going out to bars and clubs to get trashed in the days following your departure for health reasons. One of the worst kept secrets in Hollywood is that Piven can sometimes be a cool guy but often turns into a real dick now that he's a big star, so even if going out wasn't a problem with his alleged condition he should have shown a little tact by opting to stay in for a couple of weeks. The good news is he now has an awesome nickname.

UPDATE: The National Fisheries Institute has posted a video response to Piven's interview on Good Morning America, using research to back up their stance that he's completely full of it. You have to wonder, if Piven's story is true, why isn't mercury poisoning common in Japan or other countries where the average citizen eats a ton of fish? Sounds pretty fishy to me.