The murder-suicide theory was widely accepted here, with many folks also being on the fence. What I'm questioning though, is if it's possible for BS to bound his wrists so tightly as to leave markings, and then remove himself from being so tightly bound. Put your wrists together and imagine securing something tightly around them with your own hands. Then to remove it? I really don't know if it can be done, no matter how intelligent BS was.
i think just use rope or a zip tie and rotate or turn your wrists back and forth so as to leave marks. Keep scissors or a knife handy, pick up the knife or scissors, turn the blade towards your stomach and cut the ligature. Its easily done actually, I did it many times as a teenager doing magic. Just imo, it is certainly possible, may or may not be what happened.