Episode 5.5 [Rewatch]

[Silktie]

I'm with Mr AC. By the time Harry has to go and identify the body, he knows it's not Ruth. They may have organised it all whilst he was in jail, but by the time he gets that call, he knows what's what. His reaction to the call is, to my mind, him mourning the loss of Ruth. Because even though she is still alive, once the fake dead Ruth is found and 'identified' by him, the real Ruth MUST leave and the process is irreversible. Thus the real Ruth is also in effect dead to him from that point on.