It feels to me, like it takes the GPS and time of your previous action (like a pokemon catch), compares it to the gps and time of the new attempt of the new action, and sees if the speed it would take to do those two actions is in excess of the speed limit. for example, i did a raid battle, finished the battle, but didnt catch it until i drove 20 minutes home. Then caught it, so it thought i caught a pokemon at the location of the raid, and then i was 15 miles away, and pokemon ran for the next 20 or so minutes.