Bah. I find it very unlikely Eb or anyone could have perfect control in a situation like that even if Eb had control of her. I think it more likely that Eb either has foresight or has a better understanding of what Mavra is after. It is clear that Mavra has found Harry useful to her, which is why she really hasn't planned to end him. Eb likely has his hand in things. He may pretty much know how things will tend to play out and really didn't think Harry under the circumstances in BR to be in much danger.
Some of my crazier Wag's:
I've liked thinking that the Murphy Family Reunion will somehow, someday get associated with a Fae Family Reunion. Maybe with Mother Murphy taking on the role of one of the Mothers, Murphy's brother(s) as some figures, etc. I've thought that perhaps the Murphy family reunion will get transported in time, something like may have happened in the Unseelie Incursion 1994 when Milwaukee vanished from the map and was replaced with untouched forest. Yes, I realize we don't know it was 'transported in time,' but we do know it seems the ancient forest was 'transported in time'. It stands to reason that Milwaukee may have been too. Anyways, I have this idea where Eb has this inkiling of who Mab's true identity, etc and gets to meet her/Murphy for the first time. Then, they go on to a family reunion where the Blackstaff stands on the sidelines as one of the future/past/alternate realities' Mothers (Mother Murphy) tends to the extended family.
Anyways, those are kinda my wandering thoughts.