I’m pretty sure votes like this require a certain percentage of the population to vote anyway. Like… the vote wouldn’t count if there was only 15% voter turnout.
ultimately, a majority of the country had a chance to vote and a majority decided (by a slim margin) that they wanted in.
The other issue as you stated was authenticity. Of course you’ll have natural dissenters. But a lot of evidence does indeed point to interference. Like people asking the poll watchers where to collect their money and becoming upset they won’t get payed for voting no.
European nations and the US presently have boots on the ground?