There are many events where bronze is won after having to compete for it head-to-head (1-on-1 individual events like wrestling, or same for team sports)... so they just won in a situation where a loss meant no medal. They likely had more rounds before where a defeat meant elimination.

A lot of psychology probably goes into the backs against the wall scenario. Not only that, 3rd place in typical tournament bracket style is where you might see underdogs rise to the occasion.

So third got what they could ultimately achieve, second failed to do so.

* I have no idea which sports were analyzed, but as a previous athlete in a few sports the above is something Ive experienced.

* Just read the 10 other comments stating the same thing before I did.