Looking at the gun from the rear and holding it upright, does the bolt handle stick out slightly above or below horizontal? It should be slightly above horizontal to be all the way open on the A-bolt and free to move rearward in the ways. Slightly down, and the lugs have already started to engage. It isn't much different.
Assuming the bolt really is open, you've done the equivalent of sticking an unlubricated case into a sizing die, and that can cause it to stick severely. Hammering the bolt back may break the extractor or it may tear the rim off the case. A truly stuck case can be very hard to get out. I have had to resort to etching them out of a sizing die after an RCBS stuck case remover tore the head off the case. You might have done better to force the bolt closed and shoot it, but now that the bullet has been pushed back, that carries a significant risk of creating excess pressure. It depends how much it's been set back and what the load was?
So, you've got a heck of a mess. It's another example of why reloading for others is risky. Train them to use your equipment, but let them load for themselves so they keep track of their own components.
What to do next? If you have already pushed the bullet all the way into the powder, I would carefully see if I couldn't pour the powder around it and out through the barrel? You would have to point the muzzle down and use a cleaning rod or small wood dowel to keep the bullet from dropping into place like a valve while you do this. Maybe you would have to jiggle it?
Once you have the powder out and the bullet well back in the case, you can close the bolt and fire the primer. The bullet may or may not jam in the throat doing this, but you can get a 1/4" brass rod at Lowes and use that to tap it back in with if it does. You would then hammer on the brass rod to drive the case back and the bolt open. Driving it straight back against the bottom of the case will tend to stretch it rearward and to narrow it, like stretching any tubing.
If the bullet is still held by friction in the case mouth, it is dangerous to have your hand over the muzzle and push on it. The mainspring is cocked. I can think of ways I could set up to push the bullet the rest of the way in while avoiding exposing myself to a bursting receiver or barrel, but I can’t recommend you do this yourself. It may be time for professional help. Calling the factory service people may get you a place to take it. I don’t believe it is safe to ship with the round in the chamber. It needs to be treated as a loaded gun, even with the bolt not fully closed.
The only other thing you might try is to wrap the gun in plastic (for condensation protection) and leave it in the deep freeze overnight. Brass shrinks a little more than steel for each degree of temperature drop. It isn’t a big difference, but might let you pull it open? You could also do this before trying to knock the case out with a brass rod as I described above.
Be very careful and good luck.
Nick
I'd try the wooden or rubber mallet thing before getting in front of the bbl.