SS, forgive me - I'm not picking on you here. But this is not what it's like at all.
When you find a loved one who's recently died (and I mean measured in hours, not like, a week ago) unexpectedly, in your home, MY experience is that your mind doesn't turn to "insect activity".. or anything of the sort.
You see the person you love lying there, and they are not "a shell", sorry -- it's them, but they are not moving or breathing... "death" is a very hard thing to accept in that moment, and maybe some hours after.
A part of you knows they're gone, of course-- but another part is screaming that they can't be, and so, even though he was about as dead as dead gets, we still shook him, pleaded with him to wake up...
It's a crazy moment, quite literally. I don't think words adequately get across what it's like.
So there's a POV from somebody who HAS found a loved one dead, unexpectedly, in their own home.
Trust me, you don't register smells, potential insect activity, etc. We didn't even register the obvious fact he was in rigor, for a while...
I don't think there's any way to judge what they 'should have' done, or ascertain that what they did after discovering her body was 'wrong'. From my experience -- yeah. This stuff just didn't enter my mind, and IF it had been a crime scene, I would have contaminated the hell out of it. Because keeping the area pristine is about as far from one's thoughts as it gets, in a moment like that.