That's the kind of information that's hard to verify since it's secret, but two things
1. Generally speaking, nonfiction that doesn't at least stretch the truth tends to be boring as fuck, and an unreliable memory or even bias doesn't negate the category of nonfiction. Even a story that says "I imagine," and then makes something up -- no matter how outlandish they get with it, is still telling the truth, because it concedes to the narrator's imagination. But whatever it describes can still be vivid and enduring. There's a surprising amount that creative nonfiction can claim as nonfiction.
2. Knowing a significant number of trans folks, and relying on my own experiences with gender, I can say "sneaking around as a woman" is at least feasible and rings true.