True, this post contains speculation on some matters, but if a professor at Cornell whose work focuses around distributed systems who authored the selfish mining attack isn't an "expert," then I don't know who is.
It was all speculation, and it is inconsistent in its inputs -- on the one hand it disbelieves what MtGox claims, but on the other it takes historic claims of security (that keys were in cold storage) as proof of other conclusions.
Speculation that is based upon cherry picked belief and disbelief might yield the conclusions that one wants, but it adds little to the information pool.
And regarding claims that keys were in cold storage: Maybe, but one thing I think we're all learning from these amateur hour platforms is that a lot of claims aren't backed by reality. They have "Top men" working on their security. "Top men".