So apparently my boss knows the "new senior dev", which I will call 'B'.
Program which I worked on for a year, my baby, is doing fine. Suddenly B decides to update it to "standardize it", against my suggestions/protests. Fastfoward to the following morning, I get to work and there's a bunch of emails from B waiting for me. I'm like "Well there's a meeting in an hour, so no point in answering all of these". 30 minutes go by and then boss shows up in my team's area. Asking for me.
(I didn't know this at the time, but apparently boss knows B. And thinks that B is this amazing programmer and super nice.)
According to boss, B has been trying to contact me all morning about my program failing.
It is at this moment that my mentor stands up to defend me. She basically tells our boss that B is a piece of shit. And I'm just loving it, ++ to mentor for bring awesome.