I've seen paddles from several manufacturers break, so I don't think a single incident should freak you out.
The explanation might be anything - a flawed build, through to a dropped paddled that caused a tiny crack through to hitting a rock.
99.9% of the time paddles (and skis for that matter) won't break, but there are always exceptions to the rule. Both paddles and skis are built to be light and that inevitably means that they can and will break given the right circumstances.
Rob
Currently Epic V10 Elite, Epic V10 Double.
Previously: Swordfish S, Evo II, Carbonology Zest, Fenn Swordfish, Epic V10, Fenn Elite, Red7 Surf70 Pro, Epic V10 Sport, Genius Blu, Kayak Centre Zeplin, Fenn Mako6, Custom Kayaks ICON, Brian's Kayaks Molokai, Brian's Kayaks Wedge and several others...