Reactions to when things have gone wrong

A good manager is even handed. So when one of their team makes a mistake in a piece of work - it happens to everybody at some point - this is treated proportionately. It may need a supportive discussion looking at how to avoid it happening again but the manager will make it feel safe to have this discussion. Ultimately, the manager takes full responsibility for the performance of everybody in their team. The manager places themselves in the "firing line"  and protects their more junior staff.

A bullying manager reacts disproportionately. If a victim makes a mistake of any kind - however small - this may be seized upon by the manager. Its importance is exaggerated. The language used emphasises this. It becomes a "major failure" or "unacceptable". It is regarded as "yet another example of poor performance" and so on.

Rather than take responsibility themselves, the bullying manager is quick to blame their subordinate(s) publicly for any mistakes, In order to side-step obvious questions about why they did not intervene themselves to prevent the problem, the bullying manager also has to fabricate  plausible reasons for their ignorance: the victim is "secretive" and "deliberately covered up" what was going on.

This starts to become self-fulfilling, because after one major over-reaction, the victim is hardly going to be relaxed about drawing attention to anything else that is not going well.

In a good and cohesive team, the members support each other. Where one or more individuals behave dysfunctionally, mistakes by one team member may be broadcast by another or deliberately brought to the attention of the team leader and other more senior staff. Good team members will try to step in and support each other. Dysfunctional team members may relish a problem and do nothing to help.

In more serious cases of abuse, the manager may deliberately engineer circumstances in which things will go wrong for their victim. They may package work with too little time or too little information to be realistically achievable. They then exploit the resulting problems as justification for further bullying activities directed against the victim