ARRAKIS,
I wonder, if it will be possible to hear it on the CVR. That's, as I understand it, one of the main goals of the tests with the second aircraft. To hear what was pressed/switched/etc...
As far sa I can understand, it's impossible to find any material proof of pressing unarmed button. I have rised this question about УХОД button before, as well here as on aviaforum.ru, and common opinion is that without arming approach mode on АБСУ, all this buttons are not even powered. Also it's not tumbler / toggle switch, which make loud noise when toggled from one side to other.