We make decisions based upon the available information, not the information that arrives next week or next year, but upon the information available now.
Those who challenge decisions on the basis of new information are engaging in a gross act of unfairness. The new information was not available when the decision maker had to decide. An employer may decide to terminate an employee based upon evidence that is subsequently revealed to be weak, but if the employer, given the available evidence at the time, was making a reasonable conclusion, then the employer has behaved properly.
Those who use new information to criticize the earlier decision should bear the burden of explaining what the basis of their decision would have been had they been confronted with the same range of information available to the decision maker they are assailing. In my experience, these individuals offer only vague explanations as to how they would have avoided the same conclusion. They casually dismiss persuasive evidence and ignore the possible downsides of the decision they so warmly embrace.
Their criticism raises an ethical question. If they are so adroit at ascribing blame to those who had to make tough decisions, does it not indicate that they will be just as slippery when it comes to avoiding responsibility for their own actions?