Autopilot shuts down when it can't handle the situation it's in. This doesn't help it "avoid blame" at all. Because Tesla considers Autopilot implicated in any crash that happened within 5 seconds from Autopilot being disengaged.
> To ensure our statistics are conservative, we count any crash in which Autopilot was deactivated within 5 seconds before impact, and we count all crashes in which the incident alert indicated an airbag or other active restraint deployed.
NHSTA's reporting requirements are even more conservative:
> Level 2 ADAS: Entities named in the General Order must report a crash if Level 2 ADAS was in use at any time within 30 seconds of the crash and the crash involved a vulnerable road user being struck or resulted in a fatality, an air bag deployment, or any individual being transported to a hospital for medical treatment.