This may be a bug for the BGT install.
Imoen has two possible BCS files sitting in my Override folder. One, BGIMOEN.BCS, has a lot of code that I know has been firing (girdle discussions etc.). The other, BGIMOEN2.BCS just has some script to initiate dialogue with Gavin - something about a finger?
I never got to any fingers (?!) in the romance, but if people have been having trouble getting Imoen to talk about them, that might be why.