Mysterious Switch

From a hotel window, or across a very busy intersection you notice an old homeless man standing on a milk crate, ranting about something. He’s holding an illegible cardboard sign scribbled in sharpie. As you watch, a black SUV pulls up next to the old man, and 2 men in black suits and sunglasses jump out. A third MiB pulls an old man out of the car. The original is shoved into the car by the first 2 MiB, while the replacement is pushed up onto the milk crate and handed the sign. The suited men all get back into the SUV, and pull away out of sight.

If questioned he will claim that:
1. He was held in a secret government facility while a clone/android/shapeshifter took his place. They tried to wipe his memory, but he remembers!
2. The agents shoved him through the car, but didn’t replace him.
3. He’s a time travel subject, and they needed to get his younger self to send him to the past to complete the circle.
4. Don’t know what they’re talking about, but will make something up for a donation.
5. Is actually a government agent who’s replacing an alien.
6. Is a replacement/upgrade android, and the old one is being brought back to Eureka for study.