I've not had that specific misfortune thankfully... the only distributor I've pulled off this engine was one that had rusted into place so it wasn't 'pulled' as much as 'smashed.'
That one never went back in.
Was the distributor relatively easy to remove? If it hesitated a lot it may have pulled the shaft up with it and cocked it over to the side when it dropped. That would be a serious pain in the rear and your worst-case scenario.
If the distributor was out for a long time, corrosion can make it very hard to push down so you might want to clean it and the block up some. It may not be hanging up on the oil-pump shaft but rather trying to go into the block.
Does the shaft move around easily in its locating-ring? If so you could try stuffing some grease down there to hold it reasonably steady and center it as best you can with a screw-driver and try stabbing it again. Repeated up & down gentle 'hammering' motions while twisting the rotor back & forth have always done it for me. The top of the pump-shaft should be tapered so it goes in provided it's lined up with the flats of the shaft.
This thread has a few ideas for you too (like bumping the engine with the starter just a little to get things lined up better while someone's pushing down on the distributor (carefully and without the rotor so they don't lose some fingers))...