Editing Dragon nbt may result in crash

Dragon seems to be occasionally causing crashes when its nbt is edited. So far I found it crashed before once when I edited its Rotation by entitydata as well as through /tp which crashed the moment the command was run from chat. In command blocks on a 20hz clock, I am also editing the dragon motion and DragonPhase tags as well as NoAI and Silent tags and some of these also appear to occasionally cause a crash. Not sure if it occurs with other tags yet. See attached crash report.