I don't like that the article doesn't source that 10,000 number. It makes it hard to verify, and therefore hard to trust.
10,000 released to non-family members doesn't mean it was all traffickers - could have been family friends or the like. Also, without a source, I don't know how they came up with that number. Were they not family at all? Are we sure, or did they just not fill out the form? Or was the form lost?
I'm not being difficult, these are just the questions I have when presented with a tidy number. But we know it happened at least a few times. Again though, was releasing children without background checks the process, or a mistake?
https://www.washingtonpost.com/national/failures-in-handling-unaccompanied-migrant-minors-have-led-to-trafficking/2016/01/26/c47de164-c138-11e5-9443-7074c3645405_story.html
It looks like the problem was people not following the policy, not that there was a policy to just give the kids to anyone. That's a tough one. For me it would depend on if it was a resource thing, or part of the UAM surge that happened and they let processes slide. If Obama knew that resources were needed and didn't provide them, then you could say this is his fault. If not...