Weird thing though: when I log in as him, I am able to see "upgrades" to almost every plan we have (he's the only one that is showing this- he shouldn't be allowed to see this).

Sounds like you've a configuration problem somewhere then. He may have CB Moderator permissions. Review the Moderator View Access Level parameter within CB > Configuration > Moderation then check the view access level selected and ensure it's correctly configured.

I've no idea then. PM backend super administrator login credentials and will take a look.

Ok, there's no basket because the plan is free. In that case it's activated instantly and there's no need for a basket (since baskets are invoices.. nothing to invoice). The access for the plan "International Trainee Membership" is also set to Public and there are no conditions on it. So based off that information the user should of course have access to it. You also do not have upgrades to it disabled, but you do have "Propose spontaneously plan for upgrades" set to "No: hide this plan from upgrades and from access proposals, unless specifically included in URL". This means all a user needs is a URL to the plan.

To summarize the user has access to it. You've no ACL or conditions preventing access to it. There is no basket trail because it's a free plan and doesn't generate a basket. They were able to subscribe to it because an admin gave it to them. There is a history log of the plan being subscribed to (2 entries) and the user who subscribed them to the plan was "acehovin" (a Super User) based off the log. Within CBSubs > Subscriptions click the number in the Change Log column to review for your self.

I don't see any issues here. It all seams to be working as you've configured it.