It might be possible to be boosting that much..... You have to take into consideration he said he is running stock heads, you would be supprised, the volumetric efficiency of the engine may not be that great due to the heads so therefore he is just pushing more boost and creating higher air intake temps. Its very similiar to installing headers on your truck, your boost may drop a little but volumetric efficiency has increased as well as hp but your boost is actually a lower psi.
This would also explain Torspd theory of why he isnt running a higher hp with that amount of boost, the block and cylinders are probably not even seeing that pressure, I would be interested to see if that block could handle it as well as the stock toyota head gaskets. Im looking forward to seeing that new sleeved block that ttc performance is working on.