The HuggingFace hack isn't OpenAI's responsibility because they hosted it. It's their responsibility because they directed it; it was part of their own internal benchmark run that they fully controlled.

If a third party uses a model created and hosted by OpenAI, I don't think OpenAI should be liable so long as they implement acceptable security controls. Same as if a site hosted on Cloudflare or GCP is doing something dodgy, Cloudflare/GCP aren't held liable so long as they respond to abuse reports.