AITAH for potentially ruining my boss’s life and career

So I (29F) work as a business consultant for a company that serves a specific industry. Thus, clients expect us to be very knowledgeable about their business, the industry, trends, you name it. We also have a side business where we sell same clients data and analytics services. So we have a business model where Account Managers manage relationships, take us to potential leads and we nail the sale if we can demonstrate our ability.

A few months ago, the management decided to hire a guy from those fancy Strategy Consulting companies that sell you 40-slide deck that nobody can understand or implement but pay millions for. The guy comes to the office strutting like a peacock, while having zero knowledge about the industry. We assume he’ll observe and learn for a while, but no. He needs to be “that guy” and inserts himself into all account meetings, identified leads, comes with us to sales pitches, etc.. It would’ve been fine if he kept his trap shut in the pitches, but he manages to embarrass us by saying either meaningless stuff or in some cases the exact opposite of the pitch message.

When he started costing us sales, the no-nonsense account management team started secretly organizing sales pitches on slots he cannot possibly attend, and took me instead. Not tooting my horn here, but I had the best sale numbers and relationships with clients. Soon douchebag noticed this and tried to actively sabotage me by assigning me to a global project managed from another country in a time I would be on extended medical leave. I started working, informed the project team about my leave, and that I would ask the douchebag to assign someone else for that period. All in writing, cya. Douchebag said ok, was very pleasant, wished me well etc., and I went on leave. When I came back a few weeks later nothing seemed amiss. Then hits the performance reviews, and douchebag tells me I got lowest score as I left a project, understandably because of a medical issue, but my lack of planning and communication with the team and himself was an issue global performance review team couldn’t overlook.

I got pissed, escalated to our local HR, but nothing came out of it. If local HR closes the case, I have no further escalation path. Still I kept the receipts, and in the meantime upped my game. I was selling so many projects that we had to bring in teams from other affiliates. All my clients were asking that I personally lead the project, causing me to lead 6-7 projects at once. I didn’t mind the overtime, as I was waiting for my time to come.

See, every year the region department heads and HR lead visits affiliates and that time of year was coming. I calmly walked into the GM’s office, gave my notice (that would end exactly the same day as the visit), explained my reason, and walked out. During the notice period I didn’t slack, worked even better, and the day of the visit started packing my shit up. GM’s assistant called and summoned me to his office. When I went in, douchebag and all bigwigs from the region were there. Bigwigs asked why I was leaving. I said due to unfair treatment and performance assessment. Douchebag jumped in and spurted the nonsense about unprofessional behavior. I took out my receipts and left them on the table. Then I said I had to leave, and they let me go.

I moved on to a much better job now, and the first week is going ok. However the team from the old job told me the douchebag got suspended for falsifying records, unprofessional conduct, and a bunch of other stuff HR thinks can stick. It may make the guy unhireable if they stick, and I would be within my rights to sue. My friends are understanding, but my parents are saying I shouldn’t have done it as I was already leaving, and the guy can lose everything. I don’t know, doesn’t he deserve it though?