I would hope that if Ethiopian Airways cannot accept the report's findings in the light of clear evidence that their airline will be banned from using other States' Airspace.
This is not how things work in an ICAO environment.
The airline can say what it wants and dispute any investigatory findings and recommendations.
Whether the believe them or not, or just want their investors to have faith in the airline is immaterial.
It is up to their regulator to take any action they deem appropriate to follow up. For all we know there is nothing now to be done if the airline has already addressed any possible issues without admitting legal culpability.
For the rest of us aviation professionals, there is only the lessons learned in our own minds