This is from the latest episode of Castle (season 7, episode 11). Please take note of the guy marked with a red arrow:
He’s standing there, holding his super-sized coffee to go, staring intensely
at past the camera. I wonder if he’s got anything to do with production?
Hm. Now he’s on the other side of the road, trying to look harmless. Wonder how he got there, but no matter! Instead, focus your gaze intensely on the guy with the bright yellow backpack, helpfully marked with yet another red arrow. Also, observe this harmless young man wearing a scarf. He’s looking down, because he’s not involved with production in any way.
Now would you look at that … the guy with the backpack, in an entirely different scene, over 20 minutes later! But that’s not all …
.. here’s the guy with the coffee again, and who is he talking to? The young man with the scarf! It’s a small world …
… really small:
I found that one later, but the scene is actually at the beginning of the episode, when Beckett and Esposito first visit the school. For comparison purposes, I’ve added a blowup of the backpack wearing guy in the third picture – they are identical in every way. It’s really okay to reuse background extras, but if you do, at least have them wear stuff that doesn’t make it so easy to identify them.
Talking about easy to identify – everyone knows Castle isn’t actually filmed in New York. While they try to cover it up by putting NYC taxis and signage up, sometimes they just can’t help themselves:
One quick Google search reveals that the historic Haas Building is at 219 W 7th Street, Los Angeles. Would have been easy to avoid that one by just shooting a bit down the road or having Castle’s head covering the background …
… and waiting for the bus to pass before rolling the scene would have been a good idea too.