"He's broken. He's broken," Hamilton said in an interview Friday with The Associated Press. "I've never seen him even remotely like that. It doesn't please me to see that."
Hamilton rode for Armstrong's U.S. Postal Service team during his first three Tour de France titles. Hamilton's public confessions to doping -- first in a candid-but-halting "60 Minutes" interview in 2011, then later in a tell-all book that came out last summer -- provided key evidence in the case against Armstrong.
On Thursday, Armstrong's interview with Oprah Winfrey aired, and the cyclist admitted to using performance-enhancing drugs to fuel all seven of his Tour de France victories.
Hamilton, who said he felt a huge sense of relief after telling the truth, applauded Armstrong's decision to come clean, calling it a "big first step," but only a beginning.
"It's what he does moving forward," Hamilton said in a phone interview. "He's saying some of the right things now but the proof is in the pudding. If he just goes and hides away, people are not going to be happy. But if he does the right thing, speaks to Travis Tygart and WADA and tells everything he knows, that's going to make a big difference."
Both Tygart, head of the U.S. Anti-Doping Agency, and World Anti-Doping Agency director general David Howman have said Armstrong will need to offer more than a televised confession to make amends and possibly have his lifetime sports ban reduced.
While admitting to doping in his interview, Armstrong contradicted a key point of Hamilton's: That Armstrong told him he tested positive during the 2001 Tour de Suisse and conspired with International Cycling Union officials to cover it up -- in exchange for a donation.
"That story wasn't true. There was no positive test, no paying off of the labs. There was no secret meeting with the lab director," Armstrong told Winfrey.
Asked about that, Hamilton told the AP: "I stand by what I said. It's all out there. I don't know if it's a legal thing, or why he said that. It doesn't really bother me that much."
Hamilton was also among numerous riders who described the immense pressure Armstrong put on them to take part in the doping. Armstrong told Winfrey nobody was forced to dope.
"Nobody took a syringe and forced it into my arm. I made that decision on my own," Hamilton said. "But you did feel the pressure. When it was all set up for my first blood-doping experience in 2000, when I flew to Spain on Lance's private jet, I don't know what would've happened to me if I'd said, 'I'll stick with EPO but no blood doping.' I assume they would've been angry about it. For me, it was a no-brainer."
Armstrong said he had reached out to some of the people he felt he owed apologies. Hamilton has not heard from him, however, and didn't sound like he was waiting by the phone.
Hamilton called the entire episode a "huge life lesson" and said Armstrong can help the sport if he's willing to do more, especially if it involves providing information about doctors, managers and other higher-ups in cycling.
"There are still a lot of bad apples in this sport," Hamilton said. "Lance Armstrong did not act alone. There are plenty of people out there who still think they got away with it. I don't think he wants to rat anybody out. But he didn't do this by himself and he didn't learn this by himself."