Did some more digging. It’s theoretically possible for NO from beet root powder that binds up in red blood cells, to cause edema. RBC will release their stored NO in an hypoxic (low oxygen) environment.
So if the client has poor circulation in his/her hands and feet, there could be an excessive dumping of NO locally causing fluid/blood leakage.
The protective effects of NO are more likely to override this pathology, but it is possible.