Bob was hired as a senior, but his performance and attendance were subpar at best. This gave Alice (the manager) and me (the team lead) grounds not to extend his contract, which, given the cultural context, is almost synonymous with firing. We informed him of our decision a few months before his contract was due to end.
A while later, he told me that he understood our decision but would like to give his best effort in his last few weeks. His goal was to at least earn a nice reference from us. Most importantly, he mentioned that the reason for his subpar performance was a personal situation that the company's doctor was aware of.
After that conversation, his performance completely turned around. He went from being someone others felt uncomfortable sitting with to a delight to work with. The quiet person suddenly became a major contributor to many discussions, and his energy increased significantly. The team and I are now saddened by his imminent departure. During this time, I also replaced Alice as the manager, which gave me the chance to mentor him more directly. I am now almost confident that he would be an excellent addition to the team.
HR tells me that it is possible to extend his contract for a few months instead of a full year. I'm considering offering him a new contract if he's interested. However, since the law forbids me from probing into his personal situation, I would like to ask him how he sees himself performing if he were to get a new contract. In other words, is he performing this way now because he has a reason (getting a reference for a new job), or because his personal situation is resolved?
How can I have this conversation without getting into his personal situation or questioning his integrity?