I don't really get what you're saying here mate.
Moshiri doesn't say much publicly, and, tbh, when he does he makes a hash of it, but I don't recall him distancing himself from the decision ?
Bottom line is, for whatever reason, what looked like a decent decision didn't work out, so Koeman's been fired. When a boss hires someone, and then, not long after, fires them, they might not shout from the rafters "I got it wrong", but that's what they're saying.
There are legitimate sticks to beat Moshiri with, but I don't think this is one of them.