Yeah, sounds more like a TIA (transient isthemic attack) than full blown stroke. I had one about 20 years ago. First time I knew I couldn't drive. Right arm numb, leg kinda dragging, slurred speech, blurred vision.
Had the wife drive me to emergency room. By time I got there, it was over.
Been on one aspirin a day ever since. No recurrences. Much later I attributed it to using a vibrator around the back of my head and neck to relieve a stiff neck. Duh, not a good idea. Think I jarred a clot loose. Just my guess.
Sure got my attention though. Led me to try to relax more and smell the roses. Like many people, I had my share of stress. The TIA eventually became a wakeup call that I think has helped me to a better life. Hope your father-in-law recovers fully.