RE: Managed dismissal
The worrying thing is that the company seems to have had no idea how bad your LM was, or any way of actually catching people like that and dealing with them.
I was once summoned to a Friday Morning Meeting with one of the owning partners (small company so I was used to speaking to them, and unaware of the reason). Turned out to be a 'disciplinary process' meeting. I was presented with a letter listing 6 complaints allegedly made by a named individual at the client company.* There were a few things I did not like very much:
1. The letter was not even marked "personal", which I raised but received no apology for.
2. The partner had not actually received a letter of complaint, email or telephone call from the named complainant, despite having received a letter of complaint the last time the person had an issue with our performance (strangely due to the other members of the team, including the project manager who had not told them he would be in Russia for a couple of months during some critical part of the project).
3. Three of the 'complaints' were things the client had actually asked me to do, like working from home - their card key access system had very few spare cards, so the alleged complaint had expressly asked me to work from home whenever possible.
The other complaints were easily dealt with, but I was really angry, so angry I consulted a solicitor, which basically blew my pay 'rise' for that year (a humungous 1%).
After all these years, I can only suspect that there was an effort to get me out of the company, despite doing good work as I didn't 'fit' with the psychopathic management style (I did one of those newspaper quizzes on office psychopaths. If you can tick 4 out of 10 psycho behaviours by management then you are in trouble, I ticked 8 of ten from personal experience.)
I did seriously consider sending a Subject Access Request to the client requiring them to send me a copy of their complaint about me, but didn't. I reckon that really would have caused a fuss.
Now I will not claim to have ever been in the easiest 50% of staff to work with (I realise now that I had quite bad depression), but as clients kept on asking for me back to do more, I can only conclude that I did some pretty good work. One even like us so much that they turned down a £20,000 cheaper offer from another competent organisation to get me and my colleague back.
I don't know what the solution is, but it sure is a problem.
You have my sympathies for your experience, but congratulations on getting a better job. I did eventually get made redundant (3 month's pay for doing nothing) and got a better paid job elsewhere, but it did take its toll on me.
*(Even after all these years I retain the actual documentation, just in case. I am truly a sad nerd.)