Noel - Ow!
Your poor dad. I am also left-handed and heard about such things happening to kids and I guess I lucked out in that I didn't experience that.
My husband is also left-handed and, while I write with a normal-looking hand, he writes with his hand all bend around. I always thought that looked so painful!
It was many years before I learned why so many other left-handed people wrote like that. I guess, in the beginning with initlal writing instruction, they were all told to turn their paper a certain way. Well, that was just right for the right-handed people. But it was unnatural for the left-handed ones to write with their paper turned to the left like that. The only way for left-handed kids to write with their paper turned that way (top of page to the left and bottom of the page facing right) was to contort their hands around.
I guess I also escaped that torture, as I have always turned my paper to the right and I write without my hand twisted around like that.