In another case of shenanigans, it's an established procedure that if you can't physically turn up to the HoC to give your vote, you find an opponent and pair off with them, they abstain in order to give the equivalent outcome of you turning up to vote. What if they go back on their promise and vote anyway? It happened: https://theconversation.com/pairing-and-why-it-matters-in-th... - has anything been done about it? Not really.
The politics of Westminster are not in the habit of looking at every infraction and locking down process tightly. If Scottish MPs habitually voted on English-only legislation, and if it affected the outcome (which is very rare indeed as there are only 59 Scottish MPs versus 533 English MPs), there would be more concern, but as they generally don't and it generally doesn't, the formal process giving English MPs a veto on English-only legislation only lasted 5 years out of the past 316.
Did they? Wikipedia says this:
> In establishing foundation hospitals and increasing student tuition fees in England, Scottish votes were decisive in getting the measures through.[10] The vote on foundation hospitals in November 2003 only applied to England – had the vote been restricted to English MPs then the government would have been defeated.[11] Had there been a vote by English MPs only on tuition fees in January 2004, the government would have lost because of a rebellion on their own benches.[12]