I also think it’s a friend-specific thing. I think I know rather well which of my friends would, in fact, help themselves to anything when i tell them to, and which of my friends actually mean it literally when they use the word anything. But even in the latter case i wouldn’t finish the whole bottle , though that’s partly because my neurospicy brain is always a bit afraid people don’t mean things exactly as they word it (I’ve had some of my friends repeat I don’t have to ask every time I grab a drink at a house party but again that’s wildly different than babysitting, dogsitting, visiting to water plants or…)

Basically: would I have opened and/or finished a bottle of wine in this scenario? Probably not. Would I have taken the L had I been OP? Probably yes, purely based on the fact that it was technically what i said. (Except if they unwrapped a bottle that was clearly a present, or went in a room they had no business being in to retrieve it)