I'm not going to say which company it is as I don't want to spook its investors. However, I will say that they not only manufacture high-tech biological products in England (which are mostly exported) but they also employ a team of postdoctoral level scientists who do fundamental research in addition to product development. Their salaries and the fundamental research projects they do are paid for by EU research grant money as they benefit EU environmental initiatives.
Clearly, leaving the EU will terminate those EU grants unless he moves the entire company to the Republic of Ireland or Scotland (if the Scots leave the UK and stay in the EU). The idea of the British government replacing the lost EU grant money is laughable if the UK economy has contracted by 10% thus resulting in a smaller tax base.
"Your friend has bought into the scare tactics and you have fallen for his failed vision."
He is a very experienced and pragmatic businessman who has worked in biotech companies all over the world. He is not one who is prone to hysteria or panic.
I also worry about the impact Brexit will have on scientific research in the UK university sector, as that also receives EU grant funding and it relies on bringing in scientists/students from the EU and sending their British counterparts out to work in EU labs at short notice often on an ad hoc basis.
And just how much EU grant money does the UK fund?
No matter, however. As your friend is simply a corrupt rent seeker.