The rules cover a tie for first (both tying players get 1st Place Points, next player gets 3rd Place Points), and ties for second (both players get 2nd Place Points and no one gets 3rd Place Points), but the rules do not explicitly cover a tie for 3rd (in a 4+ player game).
In many cases, there are no points allowed for 3rd, and the issue is moot, but how should this case be handled when there ARE points up for grab?
We allowed both 3rd Place finishers to get 3rd Place Points. Is this the correct way to play it?
From the rules regarding ties: If players are tied on a base, all involved players get points for the best position they tied for.
The rules then go on to discuss first place and runner up ties specifically, but since nothing addresses 3rd place ties (i.e. nothing contradicts the above rules regarding 3rd place), I'd say that all tying 3rd place players get the 3rd place points.