Nigel. 65% of Labour voters wanted to remain. Discount Scotland and NI because they all wanted to remain. To have more Labour voters for leave in any English or Welsh constituency it means that in others the remain vote amongst Labour voters must have been massively over 65%. By no statistical or linguistic trick can that be true.
No statistical or linguistic trickery required.
To put it very simply (as that seems to be necessary), if the average Labour vote to remain was 65% (and that is just the result of a poll, not a verified figure) then 65% is an average when considering constituencies. To see one constituency drop below 50% would not seem unlikely. Nor would it be unlikely (in view of the total number of constituencies available) for several constituencies to have less than 50% of their Labour supporters voting remain.
Whether the extremes which make up that 65% average are as broad as I suggest they may be, there is nothing to confirm Steve Shaw's contention.