In the voice-over at the beginning of this episode MacGyver says Karen is an old girlfriend from Collage and that they were an item for a couple of years. Then a few scenes later Karen says "you didn't just expect to walk back into my life after 3 years?"
This sounds very much like it has only been 3 years since they split up, but MacGYver graduated from College/university in 1974 (see
timeline) plus 3 years ago was season 1 so we know he wasn't, and hadn't been for some time, in collage then.
I can't see it making any sense that she would be referring to how long they were together. What difference would that make if they haven't seen each other for 10 or more years?
Anyone else got thoughts on this?