Agreed, this is pretty much what I sent as feedback directly to Larian back at release, to not use Alfira if she wasn't talked to at the Grove. Along with a few other suggestions to vastly improve the scene so that the player has at least some actual narrative choice on the matter instead of having to metagame alternate choices.
Unfortunately as long as the scene remains as it is I will always keep metagaming the hell out of it. I like Alfira too much to see her stupidly thrown away like that just for a dumb shock value scene which already has a throwaway character exclusively made for it.
A seriously stupidly designed and forced scene in my opinion.
