You can easily hear that he's European because of his pronuncation of the vowels and the accent. We (Skandinavians, Germans, Austrains a few countries in eastern europe, britains and maybe Italians) got this kind of a "hard" accent and instead of americans or you, my french friend, we are able to pronounce vowels correct.
Americans for example can't pronounce an A. Becuase of their weird wild west redneck whatever accent, an A always sound like the ay in the word "may". When americans say Alexi Laiho, they don't pronounce it like 'Aleksi Laijo/Laiho' they pronounce it like Äläxsi Leihou.
(interposed question to the finns: I really don't know - is his surname pronounced 'Laiho' ,'Lajo' or ' Laijo'?)
Americans got their american accent, austrailians their australian accent, british their funny Lond'n-accent, french, italians and spanish their typical soft/stakkato accent but Skandinavians and most of us germans are almost accent-free with the right vowel-sound. That's rare.
So... what was the question again?