How did Al get into the accelerator?

[TMC]

There's a a device called the imaging chamber where Al is able to lock on to Sam, advise him. How does a lightning strike transport Sam’s body from the accelerator into the imaging chamber? It was pretty well established that Sam stepped into the accelerator and “leaped” into people in the past. Sam’s conscious occupied their body, and their conscious occupied his body. People saw Sam as the person he leaped into and others saw the “leapee” in the accelerator as Sam.