My opinion only, but I'd push back on that slightly, if only because abuse is so frequently a little visible tip of 'problematic' behavior with the rest of the whole massive iceberg out of sight underneath. You wouldn't leave your family in the care of a relative you thought of as abusive or neglectful (as in, the behavior you've witnessed or heard about from them reached a threshold of severity to label it in those terms), but you might still allow them to stay with a relative who is an overbearing, volatile control freak. You might still allow them to stay with a relative who's a bit inappropriate or a bit unsettling in ways you can't quite articulate. You might still allow them to stay with a relative who's a bit too rough or can be a bit mean. You might still allow them to stay with a relative who's a bit absent-minded or careless or has shown poor judgement at times. You might still grudgingly allow them, particularly your adult partner, to stay with a parent despite not liking how that parents speaks to or treats your partner. You might particularly allow it if all you really have are suspicions, misgivings, feelings, nothing more concrete to point to and can be convinced you're making a big deal over a small thing. And you might not know how much things are actually being downplayed or hidden from you. Over time, families often get quite good at making excuses for abusers. The abuse can become their new normal, become the baseline to the point where they really don't recognize how bad, how dangerous it really is, but do know they need to try to make it look better than it is to others who 'won't understand.' And you might be reluctant to really press the issue with your partner about the extent of your concerns surrounding a family member they love. Things that can be written off as a difference in parenting style or a clash of personalities, things you don't like but grudgingly tolerate to try to keep the peace.
What's been reported is that a friend of Josh said he didn't think it was safe for the kids to be at Oak Park Station. That could have been referring to tip-of-the-iceberg neglectful or abusive behavior that concerned him enough to worry about but not enough to force things to come to a head.
And I might have missed the part about his reaction to annoying media t0racking him down, do you have a link? I've seen pictures they've taken of him looking just kind of shattered, but haven't read anything about him shouting at them while brandishing weapons, or even interacting directly with reporters at all. There is one picture taken from a distance where he seems to be holding a sawzall with a headline about how he's furious...but that's a clickbait heading, it just says a friend of his said he's furious that his little boy went missing, nothing about threatening anyone with the tool, and it looks like he just stepped outside briefly while working on something or other. If he's got a temper, from what little I've seen he's kept it more in check under similar provocation.