Professional athletes have been known to destroy an instrument or two from time to time. When baseball players get angry during at-bats, it's not that surprising to see them break their bat in half.
You seldom see something like this happen in golf, let alone resulting in a disqualification.
That's what happened to Zac Blair, according to ESPN. During the Wells Fargo Championship, Blair whacked himself in the head with his putter out of frustration. One would think that the pain would be punishment enough for missing a putt on the fifth green, but as a rule Blair was disqualified.
But he wasn't disqualified because of the small fit he threw. Blair was disqualified because he used a non-conforming club since his putter was bent. As the rules also state, one could replace a damaged club—on the condition that the club wasn't damaged out of frustration. Blair thought he could do the next best thing but ended up paying for it.
Blair did acknowledge his mistake after: