No particular clues to point in that direction. Bar Sinister as a name is described above, I’m pretty sure Lionel Barrymore the model was not Jewish and Simon as a name is nowhere near exclusively associated with being Jewish. Witness that diligently pious oppressor of Jews Simon de Montfort.
Maybe, maybe not.
However, the name is reminiscent of Simon bar Kokhba, who definitely was.
In heraldry there is no such thing as a Bar Sinister (a bar is horizontal). There is a “Bend Sinister” which does (sometimes) indicate bastardy.
Technically you are correct( the best kind of correct 
), however the term has been in common usage for some time.