Oh, I've heard them all... Of course, "I broke it on a fish" is most common. No doubt, that's most the most "worthy" excuse.
I might be the king of fly rod breakage... I've lost count. I've busted tips in the automatic windows of my truck. I've stepped on them. I've walked them into trees. Even had a dog eat one.
My best story comes from the banks of the Madison River in Montana: I made the perfect cast...a fat brown inhaled the fly... I set the hook... bam... instant shatter. My wife later admitted that she "might have stood" on the rod tip as I was tying on my rig.
"Sorry," she said. "No problem," I responded, as the blood drained back down through my face.