Unfortunately there appears to be a discrepancy between polls, samples, how people vote in person compared to postal vote influence. While large scale fraud remains unproven the official record appears to be false and is a major concern.
What am I talking about? Have a look here:
https://m.facebook.com/notes/10152740278692513/An official investigation has had a close look at discrepancies between the postal vote turn out in the referendum versus what is actually possible based on those registered to vote in the Argyll and Bute area. It raises, without the usual conspiracy spin, serious questions on the postal vote process overall, lack of effective control; and significant opportunity for fraud and level of fraud.
What it demonstrates is that the postal vote count was not sound, it does not show that fraud was on such a scale that the referendum result itself is not sound. Nevertheless, when such fraud is possible, it makes election results questionable until the process is revised and hardened. So be careful of polls and vote share while supposedly secret postal votes are somehow known by certain politicians and are open to manipulation by government institutions. If the UK gov can influence the votes they surely will, it doesn't matter if it is SNP/Labour/Tory or whatever.