There's a comment by 'dave' - presumably, an atom dev - explaining why that's not as quick a fix as you'd hope. But, yes, as soon as I got to the part in the article that read something like '... using backtracking to handle an unknown level of nesting ...' I reached pretty much the same conclusion: stop using regexps for this!

Edit: I think it might actually be the same 'dave' who authored the article, which demonstrates how much he's learnt just by fixing this one bug.