[Physicist]

Well, assuming the 'perfection' of a black hole sounds like jumping to a conclusion to me, though I am in the laity.

But that was never just an assumption. The "no-hair" theorem for black holes was first proposed as a hypothesis by John Wheeler, and established as a theorem (by Israel in 1967 for the classical BH, and by Hawking in the '70's, I believe, for the quantum case) over a period of years. It's simple enough to state, but the math behind it is deep and difficult, and not all physicists accepted the conclusion. Roger Penrose and Kip Thorne come immediately to mind, and now Hawking has joined them.

[unspun]

But that was never just an assumption.

Well, I'd say that one man's assumption is another's findings after blackboards full of equations.