I've listened to the video and clearly the man is an expert on European constitutional law and I suspect that none of us is in a position to challenge what he says in terms of the legal issues. For example, he says that the UK is a sovereign state and its parliament is responsible for the law of the land, whereas the EU is not a sovereign state (although it seems to want to act increasingly as if it is - my italics).
The relevant bit came when he elaborated and conceded that the UK (and of course all other member states) has had to cede some powers to the EU as part of the price of being in the EU club. Some people see that as a partial loss of sovereignty but in a strictly legal sense it not. What is it though is a handing over of some powers to the EU.
Reading some recent posts in this thread it seems to me that there is a feeling that we should go with the devil we know (it may not be a devil at all to some of course) rather than risk joining forces with a new devil that might be worse.
There are some interesting comments about older people voting who may not live long enough to see the consequences - that state of affairs would include me. I made the point before that older people have lived in the UK both inside and outside the EU. There was an equally divisive debate over 40 years ago when the nation voted whether to join or remain outside the Common Market. Some who voted to join then are by definition the older generation now and may well be amongst those now wishing to leave, and vice versa.
If Brexit prevails it might be that in 10,20, 30 years time the majority of the British public will be delighted that it did. If we remain in the EU those who want to leave might, as events unfold going forward, reflect in the same time period that they were wrong and be glad we stayed in.
That's the point. No-one knows. So until the reliable sage Hindsight pontificates in 10, 20,30 years hence, no-one will.
I'm relaxed about the vote whichever way it goes. I might only live a few more years but I'm conscious that I have two generations of immediate family who, I hope, will be around for a long time and I take very seriously their future when it comes to deciding where I will put by X on Thursday.