I was thinking a hose break not a seal which would fall much faster. Which is why you would design them slow - if a hose breaks they are still a safe fall. (of course if you make them fast then you need more inspection, a trade off)

That said I'm not an elevator expert. The details I've given so far is about all I know. So if/when someone claims to be an expert and contradicts me - well they could be right.