Teach your mother to suck eggs. :-) The thing is, in the absence of someone (like an inspector) specifically checking, you can assume that anything that isn't

Teach your mother to suck eggs. :-) The thing is, in the absence of someone (like an inspector) specifically checking, you can assume that anything that isn't immediately visible uses the cheapest possible materials and the fastest, shoddiest installation. In my case, it may have been as simple as, "we didn't order enough junction boxes and we're running late as it is; just skip 'em".