Brexit is becoming a sham. The EU is trying to pull the same stunt they’ve previously pulled in other countries. They’re trying to help Brexit opposition in the UK find some loophole to make the Brexit vote illegitimate, some technicality, to have another vote. If they manage to do so, they will likely do what they did in the Netherlands and Ireland-have another vote to get their desired result, then declare that “the issue is settled” and outaw referendums.
Or, like when France rejected the EU Constitution treaty by referendum, just make the government fall and get politicians in there that would force through a nullification of the referendum by means of a new treaty (the Treaty of Lisbon in that particular case, but why not repeat a past “success”).