just for future refernce in case this does happen again and he cannot get it all out. puffers in captivity can and periodicly need to be burped.this is a somewhat easy process but can be painfull to you if not done properly.trapped air bubbles can creat discomfort in your puffer which can result in over stress and inflations to releave itself unfortunenatly over puffing can be fatal..if you notice his tail raised higher or more frequent floating he could have a bit of air trapped if it does not go away on its own burping may be nessesary to do this trap him in a net gently do not remove him of his face from the water.you must then try to get his head pointing upwards under water small air bubbles wil then be released if he puffs up simply release him when he deflates the air will then be expelled.i have to do this periodicly with my spiney boxfish puffer cus he likes to suck air when he feeds.