How does one thought here follow from the other? I’m not saying that there aren’t egregious atrocities commited in the name of mental health treatment, but it seems that you don’t even attempt to argue that that happened in the case.
With some people in some situations the kindest and most humane thing imaginable is to transport them to a mental health institution and keep them there for 2 weeks. The fact that we have that as an option demonstrates that humans care about each other and are not treating each other as trash.
The baseline, without any systems in place, is that we leave people suffering a mental episode wreak havoc on their own life and the lives of those around them. Now that would be treating people like trash.
As i say it is perfectly possible that your colleague suffered an injustice, or were more harshly treated than would have been possible or reasonable. But then say that, don’t just insinuate it.