(Quote taken from article written by Barry M. Bloom of mlb.com. You may see the full article by clicking here.)
Rich "Goose" Gossage, who will be inducted into Baseball's Hall of Fame this summer, was interviewed after touring the Hall earlier in the week. Among topics discussed were his opinions about showboating in baseball (ie. Joba Chamberlain), and how the game has changed giving advantages to the hitters (can't back a hitter off the plate without getting into trouble).
Finally, he admitted that in all his years of playing in the majors that he intentionally HIT three batters: Ron Gant, Andrés Galarraga, and Al Bumbry. Why them?
Now, I did some research (thanks to baseballreference.com). Gossage hit 47 batters in his long career. While Gant and Galarraga do appear on the list of players he hit, Bumbry was not one of them. Both Gant and Galarraga were hit in 1988 (Gant on 08/28/1988, Galarraga on 07/27/1988). Al Bumbry faced Gossage 33 times, and not once was he ever hit by a Gosssage pitch.
Here is the list of players who have been hit by a Rich Gossage pitch:
Don Baylor (2 times)
Steve Braun (2 times)
Maybe it happened in a spring training game. I couldn't find any info beyond that. Regardless of the research, you can't argue with his reasoning.