I don't know about any of those injuries first hadn, nor have heard very many reports, beyond the types of mentions that you just made.
I used to rely more on SOB carry than I have for the past couple of years. I know much prefer IWB holsters. I stil have a few SOB holsters around, but don't use them more for speed of presentation reasons than concerns about injuries.
One must be especially careful about painting one's self or innocents when presenting quickly from any behind the back carry.
I can think of few on duty LEO situations where it would really be a great choice for carry, btw.