More than the Manager, it is the Management which should look under its collars for letting such an environment develop around where people are dissatisfied and demotivated. Instead of reprimanding that manager, it would be wise for the Management to take such incidents as feedback for improving its own systems and policies.
But, from the management's point of view, if we look at this incident then surely the manager should have been more responsible in venting out his frustration. After all, he is earning his bread and butter by working(?) in this organisation and he ought to be thankful to the management at least for this cause. And if he is so frustrated then he should have the guts to move out of this company.