Not sure about the trust part. Ideally, you can evaluate the change on its own.
In my experience, I immediately know whether I want to close or merge a PR within a few seconds, and the hard part is writing the response to close it such that they don't come back again with the same stuff.
(I review a lot of PRs for openpilot - https://github.com/commaai/openpilot)
If you had left it at know you want to reject a PR within a few seconds, that'd be fine.
Although with safety critical systems I'd probably want each contributor to have some experience in the field too.
Even if I trust you, I still need to review your work before merging it.
Good people still make mistakes.
1. What’s the goal of this PR and how does it further our project’s goals?
2. Is this vaguely the correct implementation?
Evaluating those two takes a few seconds. Beyond that, yes it takes a while to review and merge even a few line diff.
You look at the PR and you know just by looking at it for a few seconds if it looks off or not.
Looks off -> "Want to close"
Write a polite response and close the issue.
Doesn't look off -> "Want to merge"
If we want to merge it, then of course you look at it more closely. Or label it and move on with the triage.
a new person with a big idea on the slightly wrong (but reasonable) channel would have more work in verification.