I have friends and family who are amazing foster parents. The destruction child welfare can do to the kids and their foster families is amazing.
Ignorance seems to run rampant in that department (my heartfelt apologies for any responsible case workers). Lying to covers their rear-ends is certainly not unheard of. I think your friends are probably in for an uphill fight ... though I hope it's not the case. Encourage them to document EVERYTHING. In case you didn't notice - my emotions run a little high on this subject.