Jumping in with my two-penny-worth, (I'm also an adopter, waves at Italian).
Normally with interracial adoptions, the adoptive parents have to show they can still reflect/promote the child's heritage. e.g. By living in a mixed community, or having links to it or to country of origin or whatever.
However for a foster placement this isn't necessary I don't think, as normally placements are made urgently to whoever happens to be free.
So maybe there is more of an issue in this case regarding heritage because the FCs haven't been doing much and are no being allowed to adopt?
I think contact with the GF would have been happening whilst in FC anyway. Maybe the FC felt obliged to allow it to continue in order to be allowed to adopt, (especially because they weren't doing a good job culturally anyway.)
Maybe SL had concerns about lack of black role models etc in the FC home, which was why she was pushing the contact. hence the rant at her front door. She's been hung out to dry, supervisors are meant to sign off decisions aren't they?
The FM seems a bit detached to me, I didn't warm to her at all. There is a bit too much 'methink she doth protest too much' about her for my liking, all the TV programmes etc.