Episode 5.5 [Rewatch]

[Agent Acme]

I don't think Harry did know the full details of the plan Adam, Zaf, Ruth and possibly Malcolm cooked up. Probably at Ruths' insistance.
For a start, Harry would never have agreed to Ruth sacrificing herself for him, so I would imagine Adam would not have given him all the details, only the ones that he thought Harry should need to know, and certainly not Ruths exile. I think the cadaver was pure coincidence, a chance not to be missed, but probably earlier than they wanted, Malcolm using his morgue contacts, to seal the deal as it were, to make Ruths disapearance plausible.
Harrys reaction to the phone call was genuine, he believed that her body hady been found, and I imagine his reaction at the morgue to the body he thought was going to be Ruth was a mixture of grief, shock and relief that it wasn't her, and the realisation of what they had planned. Its only then, he asks Adam where Ruth was.

Harry: " So, where is she?"

And again at the dock Ruth said, " I told Adam not to tell you."

Which could be taken two ways, either she didn't want the goodbye scene on the dockside, or she didn't want Harry to be told of her impending exile just yet, in case he tried to stop it, as I don't think she would have known about the cadaver.

I don't think Adam would have told Harry the full plan until after Ruth had gone, it was too dangerous for both of them, but, once the convenient body had been discovered, he knew Harry would want to know everything.

If that makes sense?

Well thats my take on it anyway.