So according to the time on the invitations The Doctor sent out in The Impossible Astronaut, they were all to meet at Lake Silencio at 4:30pm. According to the Tesselector, The Doctor dies at 5:02pm, which is exactly 32 minutes later.
You will be dead in 32 minutes
Amelia Pond Voice Interface - Let’s Kill Hitler
32 minutes, as we know, is the exact amount of time it takes the poison administered to The Doctor by Melody/River to kill him. Coincidence? Never ignore a coincidence, unless you’re busy, in which case always ignore a coincidence. Luckily I’m not busy.
There was clearly more than one Doctor at play in LKH, what with the apparent costume changes (Long coat/Tuxedo/Regular outfit) and odd behaviour, even by The Doctor’s standards.