Yeah looks like a regurge.
Often it's down to eating too much (although I don't think that's the case here). Other things to look at are temperatures (double and triple check with a reliable digital thermometer, maybe up them a few degrees too), check prey size (too big can cause regurge), something didn't agree with him (maybe check what the locusts are gut loaded with) or if he's got some kind of blockage (substrate, undigested food).
Did his poo look normal?
How's his basking?
If he's not feeling secure yet, he won't be basking too much. This will decrease appetite but can also cause a regurge. Judging by the size of the regurge I would also try slightly smaller prey.