It has been explained to me before that albino versions of snakes like that tend to be mellow in the extreme and totally helpless. But yeah, bad parenting. Anyone who has a cold-blooded pet and attributes warm-blooded behavior to it like that is - to use a word from Schild - retarded.
Never, ever assume someone that short and fat has their shit together. - Schild
I like snakes but that's bad parenting, yes. The yawn reflex doesn't mean anything in particular--you see boas and pythons do it fairly often, often a week or so after they've eaten (most of them only eat once a month or at that size maybe even longer), so I suspect it has something to do with digestion. But even a very mellow python or boa can startle if it sees sudden movement coming towards its head (it's a reflex: that's how raptors attack them when they're younger) and they may strike defensively. At that size, the bite hurts a lot and can leave a nasty wound. Moreover, even if they have eaten, a reflex bite may trigger a reflex constriction too. A big snake should always be under control of its handler.
*Per the relevant Reddit thread, a friend of the guy who took the picture said that he father pro-actively called child protective services and they gave him the OK to let the snake loose in the house. Presumably it's no more dangerous than a large dog.