Perhaps post-scrotum would be better?

Parenthesis or Parentheses? Another Americanism perhaps?

Parenthesis/Parentheses are not used to refer to prior text - Yes they are! When I take a break from sticking pins in my eyes, I might even send you a few citations.

Ambiguous denotes emotion or meaning, not appearance. Ambiguity is used in a variety of ways in order to deliberately, (or innocently), cause confusion. If it wasn't, then it wouldn't be ambiguous, would it?

Commas are often used as a reflection of speech. Therefore, by nature, they may be used, or not used, however the writer intends them to be, used.

Even poor writing is deliberate. Depends on who's doing the writing and what their intended meaning is. Perhaps it's ambiguous?