He was doing leading edge state of the art surgery where the outcomes are not necessarily either predictable or favorable. The conjoined twins could have died. Indeed, with such advanced procedures he’s probably lost his share of patients. Remember Teddy Kennedy who received state of the art surgery for terminal brain cancer and still died from it. In such there will always be at least some family members who feel compelled to blame the surgeon, regardless of whether he did a brilliant job or not. Although a Trump supporter, I’ll give Carson the benefit of the doubt here.
Here is the problem with that line of thinking. If one wants to be president, one will be held accountable for whatever goes wrong on his or her watch.
The telling part will be how Dr. Carson responds. If he does well, it is a good sign. If he minimizes it or throws underlings under the bus, beware.