The evidence isn't just scarce, there's no evidence at all.
Misunderstanding or not, Leah is clearly in the wrong here. This type of
behavior, making a public accusation without evidence in an obvious attempt
to bring a hate mob against the FSF, is unethical. It's also only detrimental
to the cause she claims to support; when people are ready to start a
shitstorm any time a trans person gets fired for any reason, employing any
trans person in the first place is a liability.
On a personal level, I don't believe for a second that Leah's accusations are