"So what is the probability of a good outcome if you can't formalize friendliness before AGI? Some of them would argue infinitesimal."

One problem here is the use of a circular definition of "friendliness" - that defines the concept it in terms of whether it leads to a favourable outcome. If you think "friendly" is defined in terms of whether or not the machine destroys humanity, then clearly you will think that an "unfriendly" machine would destroy the world. However, this is just a word game - which doesn't tell us anything about the actual chances of such destruction happening.