I like your idea of a 'screwdriver test', Mrs B! That should be a Barry Bucknall theme!
Sounds fine to me, you'd soon know if the leak made the boards rot! Anyway, the leak would have come from the back or the side, as that's where the pan meets the outflow pipe. The actual loo can't leak, unless it's cracked!
You'll be fine, never fear! Your seat is safe:0)
(Unlike a lot of others in Westminster, but we don't talk about that here)!