Calling Segwit a bug fix, is a bit political, if not adventurous use of the word.
https://programmingbitcoin.com/transaction-malleability-explained/
>Fixing Transaction Malleability means that the Lightning Network can work smoothly. Like i said. Political. And an adventure. Bitcoin drags LN along, like some High School senior forced to bring a sibling to prom by their parent. Is Lightning what and where we were expecting a few years back ? Ready to onboard billions. Or do we need yet more fixes to do that?