! One thing that kinda bothers me though, why couldn't he just tell River the plan in the first place? I mean, I know he was trying to make everyone think he was dead, but you'd think he could trust at least her to keep a secret (but then she did go blabbing it to Amy and Rory, so…..) Anywho...
Wibbly wobbly, reverse timelines He couldn't tell her before she was captured and put in the suit, and that moment was his first opportunity after.
! Things ALWAYS worked that way. It was always the robot on the beach, even the first time, we ust didn't know it yet. And pretty much every River we've met since then (aside from LKH) has been in on it and has known the trick. She's in prison, but she knows full well she didn't kill the Doctor. It's acting. Its all part of the act to convince the universe the Doctor is dead. But she gets to come and go as she pleases basically (never any problem breaking out) and explains why she doesn't seem more guilty or troubled every time we meet her. And eventually she gets pardoned. Stormcage is just for show.
! Its probably also part of the reason she has a few adventures backwards. (Its never been exactly reverse order, otherwise there'd be no point in keeping a diary… but theres a few adventures where she has to go follow up on the lie and drop a few hints and consistencies in the past.) The season 5 and 6 adventures at least were all intentionally after this one to give credence to the lie... but River knows full well they are her final adventures with the Doctor... since they're everyone else's firsts with her.
! Next season River and Doctor might follow more of a consistent straight path, but it doesn't matter so much at this point, since we have the start and end points nailed down... the middle could be in whatever order for them.
! Also, it does make one wonder about the Silence in the Library... did River really die there? I'd hate hate HATE for them to get around that, so much tragedy and poetry built into that death scene, but...
! Plus explains why when we had the cameo from Amy and Rory at the mall last episode they weren't in any rush to go to the lake to fix things, even though that was the next day.
One thing that I think is really interesting is, we're getting River's story mostly backwards, and the Doctor has a bit of a loop in his… )especially last season where he revisited a bunch of events) but Amy and Rory is basically the perspective we're consistently following as the through line.