I think of it as the same particle(electron) arriving at the same point of space at the same time but going in a different direction (in time). Pretty mangled up. And where does all the energy come from then?
It is just a change of interpretation; rather than saying the annihilation causes the release of energy, you could say the change of motion (forward time to reverse time) causes the release of energy. The effects are the same either way, remember Eliezer's dictum, "It all adds up to normality."
The energy was moving backwards in time, and was absorbed in order to reverse the electron's direction.