Bingowings said:

I don't think there are many private investigators who can follow behind someone so fast they get to their destination before the person they are following behind.

But spacetime is very bent.

Apparently, if you fly in a straight line fast enough, you'll eventually come up behind yourself. Bent indeed.

When my uncle is investigating someone, he doesn't just follow them everywhere they go. He learns their schedule and common places well enough that he can guess where they're going and take a different route to get there ahead of time. Or he'll radio to his sons where to pick up the tail so he can turn off and not arouse suspicion of the mark.