These situations are never as clear cut as they seem, in my view.
I can well understand the government being persuaded that awarding contracts to a company about which it had reservations, was nevertheless justified. Perhaps on the basis of reassurances from Carillion directors and also that they very act of awarding such contracts, provides more revenues, increases investor confidence and makes the company's failure less likely. Would Carillion have gone under sooner if the government stopped awarding them contracts sooner?
It's all too easy for serial protesters (aka Jeremy Corbyn) to throw mud around, (a) with the benefit of hindsight, (b) without knowing all the facts and (c) having zero responsibility for any of it.
"If I was Roger Federer, I wouldn't have attempted that failed backhand cross court pass".