Initially, I considered that. But if so, they did a really good job sealing it back up! I looked it over and couldn't find any sign of it having been opened and sealed back. And then I thought, why go to all that trouble just to get an extra 456M? 5 packs are supposedly exclusives, right? So the perpetrator would have had to buy two 5 packs to switch out with the other exclusive 550. Why not just put in any 1/64 die-cast laying around? Doesn't make sense, does it?that one looks like a return...where someone wanted only one car out of the 5 pack, and replaced it with a double of the 550. They didn't even put the yellow one back in the right spot.
5 packs are very easy to open, then re-seal, then return to the store.