A lot of people seem determined to find someone to blame for the many hardships of this pandemic. Some people want to blame the government for locking down too soon or too late, for too long or not long enough, for closing the schools and for keeping them open. Other people want to blame their neighbours, colleagues or inlaws for going out too often, not sanitising adequately or conversely, wilfully destroying the economy and destroying family ties by being over cautious and staying home. At the beginning a lot of people seemed to blame the population of China as if eating foods that aren't part of a normal western diet was a deliberate attempt to destroy the world order (although mercifully, that seems to have died off.).
This is a new and very contagious virus. It will spread. Nothing anyone can do will stop it spreading. This will continue to be an international problem until a level of herd immunity is reached either naturally or by vaccination. All anyone can do, whether in government or at home, is assimilate the information available at any given moment and react to it. If subsequent events show they made a poor choice they have to then deal with that.
I am not an apologist for the Tory government. I've never voted Tory in my life and I don't expect I ever will, but if hindsight is showing Boris that giving us the 5 day Christmas window was the wrong thing to do he should have the courage to admit this and revise the policy. If it saves even a few lives it will be worth it. What I hope he doesn't do is stick to the original plan because he is scared of looking weak or losing popularity.