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
I wonder if this is your idea of "remaining civil" as you requested abowe.

Honestly, if i would be GM, i would ignore such condition aswell ...
Its silly that stake in your heart, when lay in your lair cause your complete destruction ... but anywhere else, in any other case, you just laugh to that. :-/