Why not actually read the rest, given that it's a Nobel Prize winner speaking?
It is, as a matter of fact, not unreasonable to suggest that there was some Russian interference in both the Brexit referendum and in other recent US/European elections. I don't think that's equivalent to saying that Leave would not have won without Russian help, but that throwaway remark shouldn't destroy your interest in the piece.
Minford isn't quite alone, but it's worth remembering that the economists' opinion in Brexit is, roughly speaking, 5-1 against Minford et al's analysis. This alone isn't meant to be decisive -- the majority has been wrong before -- but it's worth mentioning for context.