What was wrong with offloading the standby pax? Isn't that why they are called standby?
I don't see what is wrong with the Cabin and Tech crew being pro-active in assisting to solve this problem. That is what makes companies successful. Maybe they didn't get it quite right, (I don't know as I wasn't there) but full marks to them for not just sitting back and doing nothing, leaving the hard bit to "someone else".