When we are on projects and difficulties arise, often people start to run for cover and blame other parties. The key to leadership is to keep people focusing on solving the problem as opposed to deciding who is to blame. When pressure is on, people are tired and working on complex issues, clear thinking is very important. When people become defensive, I think it blocks their reasoning power.
I recall Fred Longstaff when he said you can tell a self-actualized programmer, when he says "What did I do?" rather than saying "I did not change a thing and it worked last time." When problems arise, remember we all in the same boat and we need to solve the problem.
My advice is keep reminding the team about the problem and get everybody looking at the problem. Now everybody will see it from a different perspective and thus will illuminate the issue. Remember to keep in problem solving mode.
However some people think that competition brings out the best in people. I think that competing might help as long as one does not win by negative activity. So how do we promote positive competition. The things that the leadership rewards is part of the secret. The team must all want to solve the problem and support each other.
Playing win-lose games might give short term rewards but develops a lack of trust. Building trust on a team is so critical and the leader must work to develop this trust. Trust is so important. However people’s goals must be aligned.
I guess these things are not simple and never ideal. The key with real projects is they are done with real people who are imperfect. Sometimes it amazing me that we can accomplish some amazing things with people working on the edge of their capability. I have worked on many complex projects on the edge of technology. I certainly was not a genius but using all the capability of the team and giving everybody recognition for their contribution really helped.