Here's some Farage quotes, so you can see that there is no contradiction between the comment you were replying to (him saying it was a disaster is compatible with all this) and him still being a leaver:
“I don’t think that for a moment,” Mr Farage replied when he was asked if the UK would have been better off staying in the EU, the world’s largest single market area. “But what I do think is we haven’t actually benefitted from Brexit economically, what we could have done.”
“I mean, what Brexit’s proved, I’m afraid, is that our politicians are about as useless as the commissioners in Brussels were,” he added. “We’ve mismanaged this totally, and if you look at simple things…such as takeovers, such as corporation tax, we are driving business away from our country.
“Arguably, now we’re back in control, we’re regulating our own businesses even more than they were as EU members. Brexit has failed.”
- https://www.independent.co.uk/news/uk/politics/nigel-farage-...