In general (apart from run time code loading) one can accomplish a lot of things Erlang does in any language.

Her "how much pain and when" I think implies that she only accepts concurrency as practical when units of concurrency are isolated as that would reduce the number of shared data structures being updated, lock contentions and so on. There is some truth in there that I agree with.

But then again maybe she was just trolling. I for one do not like her tone her comment.