There have been some (unsourced) suggestions elsewhere that Unite may have to do the ballot again because of the likelihood of a successful challenge to this ballot.
Aside from everyone possibly losing the will to live in the interim, if Unite considers that a strike cannot go forward because of non-union members being balloted, it would surely take weeks/months for BASSA to fix its database to be certain that there are no procedural errors. Also, the issue of protection/continuation will not go away under a new ballot