Episode 5.5 [Rewatch]

[Silktie]

Another thing, if Harry wasn't in on the plan, was there not a chance he would have blown the whole thing at the morgue by going "Woot! It's not the woman I love that's dead!" That was too big a chance to take, so I agree with TL that there's a missing scene where Adam informs him. There are plenty of things that we never saw but which we know must have happened off screen and this is one of them.

Re Harry's reaction at the morgue, I tend to interpret it as him playing it up for anyone who might be watching, and who knows whether there aren't security cameras that Mace et al might have checked later? So it's not just about the attendant. Or it could simply be a reaction to the fact that he's just condemned Ruth to exile by going through with the identification.

And Ruth's "I told Adam not to tell you" refers to her location, not to the whole plan. She didn't want Harry to come and say goodbye, as she knew how hard that would be for both of them. Avoidance is their default position, remember.