A back story I heard at an SAR meeting from a historian: Washington wrote Howe to ask him not the hang Hale. Howe blew him off. Four years later when Washington had Major Andre and Andre was asking to be shot as gentlemen of that time were in such situations, Washington took great pleasure in saying, “NO!You will hang like the common criminal you are.” There was never any chance that Andre would be traded or face a firing squad.
As I recall it, the issue was that Washington stated that he would hang a British officer in response to Hale’s hanging. A very young British officer (can’t recall his name) was slated to be the one, and Washington spared him after the man’s mother wrote to him personally — it was something of a sensation at the time. So having relented once, he couldn’t very well relent again, even for the sake of an officer who was admired by both British and Americans. Even so, Washington informed Howe that he would exchange Andre for Benedict Arnold, but only Benedict Arnold. That of course did not happen.