Can I complain abt Senior Management?

TLDR : Got written up twice.
My direct manager recently promoted me to L4 after being a contractor for only three months. He trusts me as I got handed my first project as FT, as my direct manager leaves for vacation at the same time. This was a senior critical beta blocker project that had a short time line and four teams working together. The senior manager steps in and sees how many issues are occurring (not due to anything I could control) and sends me two people to help, whom I've never worked with on this project. The senior manager asked them to provide an assessment on my performance based on that day. I was not aware they were doing that. Then senior manager emailed me exactly what they wrote. It was some nasty stuff like I'm not doing anything right. The feedback I got was brash, rude, and direct. I can see this project is tanking and they need someone to blame. I know my ability and shortcomings and know how to evaluate my own performance to the extent that I can forsee if a deadline will be met or not.

Rewind, I met this senior manager the week before because they got two complaints about my "tone". I told her I will try to improve Yada Yada. But in tech we are all bossing each other around one way or another.
I wrote a long response explaining why I seemed "short" with an assistant with overview of all the things they did well and where they fell short. This assistant was hired BC they are friends with the senior manager and they are not qualified for the position at all. But obviously I'm not allowed to point that out.

1.) is this senior manager allowed to send random people to review my performance?
2.) would this qualify as a type of retaliation as the two events happened in a 7 day stretch of each other?
3.) as a new person to corporate FAANG type companies, how do you handle these political moves?
Thank you for reading this far.