How did the tire service, get the tire to seal different than you, with your "huge compressor"?
Large tires are almost impossible to re-seat the bead with any size compressor.
You just simply cannot flow enough air through the valve stem.
There is a product that resembles an almost slippery wax like substance that essentially fills the void to allow the tire to be filled traditionally but is very messy and from what I've seen is used on very large tractor tires.
The OP mentioned that the tire guy used a canister type tool to re-seat the bead.
Usually this is a huge blast of air that quickly expands the tire and seating the bead allowing it to be filled traditionally.