Here is the link to the original post:
“I’m just going to put this out there because I’m struggling with it. And it will probably be my focus for awhile, kind of like how something being wrong with Amy stuck with me the whole of part one.
The Doctor’s clothes are probably the most important thing in Let’s Kill Hitler. And I think we should keep an eye on them.
First, he starts out with a new coat. I don’t know the significance yet, but I have a feeling his new coat is going to be important. Where did he get it? Why was he wearing it at the start? It disappears later in the episode and he puts on his classic look at the end.
Second, no one seems to care that he just randomly appears in a tuxedo. This is connected to the computer Amelia Pond as well. We hear her say, “fish fingers and custard” to The Doctor. Although, it cannot be the computer that says it. The computer was insistent that it wasn’t Amelia Pond. Also, there isn’t any real way for the interface to make that emotional connection/memory. Lastly, we are conveniently not shown Amelia when it’s said.
So he hears this clue, it clearly has meaning to him. He gets up and goes somewhere in the TARDIS. Next thing we know, he appears in a tuxedo. You know where else he had a tuxedo? Amy and Rory’s wedding.
In Series 5, he is at the wedding and clearly has a red corsage on his chest. Then, it cuts to Amy’s house where The Doctor appears, still in tuxedo, but he is corsage-less. Although, you cans make out a safety pin on his chest. You can also make out the safety pin on his chest in Let’s Kill Hitler.
Lastly, when Amy and Rory catch him in the TARDIS after their wedding he says he was sorry he had to pop off for a bit because he was busy with something.
So, here it is: where did The Doctor go after fish fingers and custard? Was it the wedding? What was he doing when he popped off from their wedding? Where did the corsage go? We know he had a balloon that was potentially from their wedding, was there something else from the wedding or Amelia’s house that was important?
So that is what it’s like in my head right now. You’re welcome.”