 Sometimes the bullets do fail..if you have hunted enough you may have experienced this...A good friend, who by the way has shot hundreds of whitetails, told me of trying a .22-250 on little W. Va. whitetails...He shot several and had good success..then he popped a forked horn in the shoulder with a 55 grain factory..the buck bounded away, before he could work the bolt...but he could see the deer had a broken shoulder...it was lost...once I had a 225 grain Speer hollow point from a .44 break up on an antelope's shoulder..I got in another shot before  the buck got away...and broke his neck...when he was skinned, there was a huge hole though the shoulder blade, but no damage to the internal organs from that bullet...so bullets do fail..
 Sometimes the bullets do fail..if you have hunted enough you may have experienced this...A good friend, who by the way has shot hundreds of whitetails, told me of trying a .22-250 on little W. Va. whitetails...He shot several and had good success..then he popped a forked horn in the shoulder with a 55 grain factory..the buck bounded away, before he could work the bolt...but he could see the deer had a broken shoulder...it was lost...once I had a 225 grain Speer hollow point from a .44 break up on an antelope's shoulder..I got in another shot before  the buck got away...and broke his neck...when he was skinned, there was a huge hole though the shoulder blade, but no damage to the internal organs from that bullet...so bullets do fail..  
 
I agree 100%.
I will also add or point out that both the bullets in the example are excellent examples of NOT good bullet choices for the task at hand!
As I have always said, HOLLOW point bullets in conventional jacket and core bullets are not a good choice for big game. They expand too quickly and underpenetrate and over expand, thats what they are designed to do. A hunting bullet, IE Big game bullet should penetrate fully and expand slower to allow for that penetration. In the case of the 22/250 55G bullet, its a target/Varmint bullet plain and simple.
I don't think a 22 and big game hunting should be used in the same sentence. One should at least use bullets so designed... in the same way you would not go to a drag race driving a stock Yugo, you wouldn't expect a HS kid playing foot ball to be as competative on a NFL team and none of us are gonna give Jerry Micklick or Doug Koenig a run for there money shooting. 
My examples and "we" are not good choices for the tasks. Simple as that, choose the proper tool for the job.
CW