I'm all about true crime podcasts, and you're not wrong.
However, the giveaway here is "they had to cut the brace off," especially with "they got out quickly" following quickly behind.
If such a thing required cutting off - a process that would be much more dangerous to the child than disassembling it - it would have had to be designed to be permanently installed without cutting. That means welded or padlocked as opposed to bolted or latched. Besides which, building such a thing in that way requires a serious amount of effort and planning. Not to mention this is right on the heels of having had repercussions for doing that exact thing. The steel and fabric one would have had to be designed and built before normal visitation was resumed.
All that indicates an incredibly sick perpetrator, who also lied to a judge when he said he'd learned his lesson - because the thought and design and construction of the second one had to have already been going on. I find it unlikely that, in 2016, in Florida, someone who so grossly abuses a nine year old, and who is found out by their neighbor, a police officer, when said nine year old shows up at the door with the thing needing to be cut off, would be quickly released on bail.
Edit: @Speculater rightly points out that a brace, worn for such a short amount of time, could not dislocate a shoulder.
Rage-inducing stories on reddit are famously fake, and this is one of them.