What Ron said.
The whole shoulder has both the boston butt roast and the picnic roast.
What he has is either PART of a boston butt (many local meat counters sell the shoulder roast or butt roast in smaller cuts, like cut in half or thinner from the whole butt) OR he has parts of a pork loin roast is my guess.
Even smaller meat counters are likely getting either whole shoulders that they're parting out or they're getting double cryovacs of whole pork butts like you find at Sams or Restaurant Depot and are slicing and parting off of those. If you ask them for a whole boston butt or whole pork shoulder butt roast, that should clear things up.
Ask him to see what he has.
Here's a boston butt roast:
Here's a pork loin roast:
Boneless Pork Loin Roast, Split.jpg
The one pictured above is boneless. What he has may also have a bone in it.
They cut pork chops off of this (loin chops).
TOTALLY two different pieces of meat.