Looks like he spooked big time (when you lost the balance). Glad you are OK! As for falls, it definitely happens with many of us (me including). :)
Speaking of balance, in the very beginning (when you are close enough), while you are aligned quite nicely your heels are up (and that could be partially the reason why you lost the balance when he suddenly spin).
"Life isn't about waiting for the storm to pass: it's about learning to dance in the rain..."
"When we are no longer able to change a situation - we are challenged to change ourselves."
"How people treat you is their karma; how you react is yours."