Harmful workplace behaviour is often sustained by the people who witness it and say nothing.
This is the situation The Autistic Standard calls the bystander position, and it is the first tier of the framework for a reason. Almost everyone occupies it, almost no one is trained for it, and it is the cheapest point in the system at which harm can be stopped.
A colleague imitates the way someone speaks after they leave the meeting. Someone rolls their eyes when a person asks for the agenda in advance. A manager describes an employee as difficult in a way that means they asked for something in writing. A team develops a running joke about a person's directness.
None of these will appear in a complaint. Individually each is deniable. Cumulatively they establish that a person is a legitimate target, and that is the condition under which more serious conduct becomes possible.
The most common reason bystanders do nothing is not indifference. It is that they have no script. They can feel that something is wrong and cannot locate a response that does not escalate the moment into a confrontation they are not equipped for.
So they wait for a clearer example. The clearer example is the harm.
The framework teaches a deliberately small intervention, because small interventions are the ones people actually make.
Name the behaviour, not the person. "That's the second time that's come up" is available to someone who would never say "you're being ableist". Redirect to the substance: "What was the actual issue with the request?" Interrupt the pattern rather than prosecuting the incident.
Then do the part most people skip. Check in privately with the person afterwards, without requiring them to perform distress or make a decision about escalating. Being seen is often the intervention.
The behaviour that causes harm persists because it is socially costless. The bystander move imposes a small cost, in public, at the moment it happens. It does not require a policy, an investigation or a courageous confrontation. It requires one person to indicate that the room noticed.
That is why the tier exists at the bottom of the framework rather than the top. The evidence of whether an organisation is safe is not in its documents. It is in what happens in the seconds after someone says something they should not have.