I believe i can see where they get it from
That sentence which, if they had read it, would have prevented the ridiculous stake comments and associated murder scene paths? Ya, so... the result is, we have to conclude that Larian either fails at basic reading comprehension so hard that they don't understand what a conditional is, or they care so little about the forgotten realms and D&D that they're wilfully ignoring that sentence and are just running with 'generic vampire lore lol!' because they can't be arsed doing it correctly. Neither case is particularly heartening...
