Talked to/was talking to...

Person 1: His said his name was Heathcliff-

Person 2: That's him. That's the guy I talked to/was talking to.

What parameters decide which of "I talked to" and "I was talking to" is correct/natural to use here or are they completely interchangeable?

If Person had talked to Heathcliff an hour ago, which one would you go with?