Devon and Cobel *spoilers*

They've been having some recent communications and Devon has become confident that Cobel is completely done with Lumen and thinks that she could useful for exposing them.

It's the best explanation for why the most normal person on the show would suddenly think "oh hey maybe my brother's psycho boss who lied to me and who I thought kidnapped my child would be a good person to call in this very precarious situation."