Seems a bit of an overreaction. Mistakes are part of science.
I agree. They even stated that they probably had made a mistake, and were asking the scientific community to find it for them after they had spent 3 months trying to do that very thing.
If the rumor is true that the faulty measurements may have been caused by a loose wire I can understand the embarrassment. I remember spending 3 weeks trying to get a specific expression clone to work only to find that I had left out a single base in one of my primers. It was an extremely simple and embarrassing mistake and I was sure that my bosses were going to rip me a new one. They didn't, and I learned an invaluable lesson. I would hope that a colleague would have tried to talk him out of resigning. Eating humble pie sucks, but it does make you a better scientist.