Prow seems to assign Assignees who are not in OWNERS file about prow HOT 3 OPEN

Right, Prow does that for approvers after they approve a PR. I am actually not sure why it does that :D I'm not sure how your Prow is configured, it can be configured to consider GH approves as Prow approves, which I think is the case here; your review was a GH approve.

from prow.

For completeness, here's our Prow configs for the repo.

First, https://github.com/openshift/release/tree/master/ci-operator/config/opendatahub-io/notebooks (that's just CI jobs, probably not relevant).

And second, here's our global prow config https://github.com/openshift/release/blob/master/core-services/prow/02_config/_config.yaml and here's the repo specific config https://github.com/openshift/release/blob/master/core-services/prow/02_config/opendatahub-io/notebooks/_prowconfig.yaml and plugin config https://github.com/openshift/release/blob/master/core-services/prow/02_config/opendatahub-io/notebooks/_pluginconfig.yaml

from prow.