With respect, I don't think the other commenter is deferring to Facebook's abilities and openness to resolve bugs in the cryptographic process, but pointing out ways they can continue to act that align with open questions from their past.
e.g. https://www.cnet.com/news/facebook-bug-has-camera-activated-...
Where the question arises: was it a bug that the camera was on, or that it was revealed inadvertently? Hence the discussion of trust in the client. That is an instance where Facebook lost some of that trust "in buckets".
It's true that "shit happens", but when it "happens" reptitively the questions begin to emerge. I don't think that's unfair. I mean, I'm sure few people would use a stock Ford Pinto as their regular driver, regardless of Ford's intentions or engineering capabilities.