Ask them if they dialed in the new grinder with fresh beans right away. A new machine needs a full setup, not just plug and play. They might have just swapped it and kept the old settings, which never works. The burrs could also need a break-in period to settle down.

Wait, spies over avocados? That's wild! I would have just been annoyed at the line holding up. It's crazy how different people see the same normal thing. I get what @samj27 means about the little stuff, because my brain never goes to full spy thriller from the grocery store. Mine would be a sad story about someone buying one lonely avocado. This is a good reminder to look harder at my own boring moments.

Ugh, I just use a rocket blower and hope for the best.