(Young guppies just don't seem to be able to help themselves and always head for an unguarded syphon, that is why I always net the end of any type of syphon) Mind you they didn't get stuck in it. One of my large female peppered cory's got herself wedged inside a hollow rock and that was a tricky procedure to smash away the rock (while balancing it on a brick as the cory's head was out one side of the rock and her tail out the other) with a sledge hammer and not injure or squish her. Any way got her out and put her straight back into her home and no problems since, except now she tends to steer clear of hollow rocks. If anything I would keep a close eye on your cory and make sure no infections set in from any possibly damaged body parts, they are pretty hardy little critters. I even accidently 
left a cory out of water for a couple of hours while I was cleaning my pond. It had hidden itself in the lily roots and I didn't see it before I put the lily aside to concentrate on cleaning the rest of the pond. Any way I found the poor peppered and held it in some shallow water and sort of moved it backwards and forwards to get water moving back through its gills. Thankfully it made a full recovery 
. After that I was always more careful removing the lily and swirling its mass of roots around in the pond for a lot longer to make sure no other fish where still hiding in its tangle of roots and stems. And then once the lily was out of the water I would carefully scrutinse it just for any really stubborn fish, thankfully I have not had a repeat preformance.
Paying too much interest in the end of the tube she was!
