Wow, that is a disastrous interview, who let that guy go on TV? He basically just admits that that campaign promise was a lie and isn't going to happen, the morning after the vote. That woman is right to be disgusted. I didn't think it would take long for buyer's remorse to set in, but certainly more than a few hours after the vote.
In fairness to him, he's actually right to an extent.
He was part of a leave group, but not the campaign with the slogan on the bus.
He also cannot dictate that the £350million would be put into the NHS. His party has 1 MP out of a house of 650, so no real power or influence in there. He's not even an MP himself, so would have no control over the budget issues.
The people behind that leave group are MP's to a large extent, so it's really down to if they keep their word on it. I'm no fan of Farage by any means, but the interview was a bit clutching at straws. Reminds me of the LibDem "Free University education if we win the 2010 election thing". They ended up in a coalition government, but weren't the majority party. From a technical viewpoint, they therefore didn't win the election, and so didn't need to enact that policy.