I've witnessed a 2 on a par 5 before.
Without a doubt the greatest hole I've ever seen played.
The famous "railroad hole" at Castle Hayne - Hole 12. http://www.dgcoursereview.com/course.php?id=1084
Rory Joyce threw a good shot to the first turn. Then threw in a 330 skip side arm for the 2.
FTR, this hole scores like a par 5, but it's not that hard of a 3 (I've done it with 3 aviars). Well, it's a hard 3, I'm just saying it's not uncommon to see 3's.
But a 2 on this hole was the craziest thing I've ever seen in disc golf.
The Castle is my home course and #12 is a BEAST. An eagle on that hole is AWESOME -- I didn't do it...best I've had so far on that hole is a par -- but to hole out in two there is re-dick-u-luss. Would've loved to have seen that.