KlugerYid is correct.
Ubiq, KY adequately answered the questions you posed. His point remains and is a strong argument that hasn’t (and can’t) be refuted.
Syag, lack of witnesses is a separate issue that doesn’t impact this point or discussion. We’re discussing the underlying punishment assuming the criteria for warning and witnesses has been met. That is a sufficient way in determining the severity of the crime. (If there are no witnesses to a murder, the murderer still committed one of the most severe crimes even though he might get away scot-free with murder. The underlying punishment for murder is the death penalty even if the murderer avoided it due to no witnesses.) In your example, had the victim been male it would be a capital offense, the most severe of all crimes.