Oops, definitely a bit of an oversight on my part, I should have seen that coming!
I'm using the same code to loop through images on both OpenGraph and the fallback crawler, so generally OpenGraph has a limited number of images, but fallback could find way more of them.
I'm not sure what the reasonable image count is, so I think I'll add this as configurable value. And probably apply the same value to both OpenGraph and fallback, in case you want to limit all of them to 1.