I discovered why in some locations on the page lazy image loading script part was working, classes were there, but images were not appearing when in viewport. Turns out that with various page building techniques it's possible to get content filters run on any given element set more than one time. Yes, the world isn't perfect.
Solution was to simply add "lazy" to the Lazy Load disable list, so then the BJLL could ignore what it has already processed.
I'm wondering if this shouldn't be built in as a safety mechanism. Probably solves a lot of "images not appearing" threads here at one fell swoop.