I'm still catching up, but I don't see anything wrong with this statement, that there was no reason to suspect foul play. As it stands now, as far as we know, there is still no evidence of foul play. There was no bloodshed, no witnesses that saw an abduction. So as far as we know the girls could have crawled in a root cellar and been trapped, walked to the river and been swept away, fallen down a well, etc. I don't think any of those are likely at this point. . .but we just don't know.
I also think just because Abben said there was no reason to suspect foul play doesn't mean that LE wasn't considering it. They were interrogating the parents, checking out RSO's, etc. I'm sure they were looking at possibilities. BUT at that point there was no evidence of foul play. . .and they had to rule some things out. . like the girls drown, or were simply trapped somewhere.
I don't think for a hawt second that LE dropped the ball here. I feel pretty secure that they were considering all angles while they were ruling out something accidental. If there was no evidence of foul play than that's what they had to work with. It doesn't mean that they weren't considering it simultaneously.
MOO