Tell me about a time you had to deal with a difficult person at work. How did you handle it?

"There was someone on our team who was going through some personal issues and suddenly behaving very defensively towards everyone on our team. They finally took offense to me asking if they needed help with a job they'd been tasked to perform, which, based on previous conversations, I knew was outside of their comfort zone. They reacted defensively to me, and I remained calm and asked why my offer of help was offensive. They offered several banal reasons, which I was able to dismantle by using non-defensive techniques. Eventually, they acquiesced and brushed the matter off. A week later, they thanked me because it prompted them to take a closer look at what was going on with them, and it turned out a migraine medication they were on had side effects that caused behavioral changes. They switched medications and soon went back to being more their usual self."