Hamilton, mean-spirited to the end, said this in his dieing declaration to further injure Burr, even though the seconds from both sides and the attending physician told slightly different versions. Burr characteristically kept mum.
Can't agree with you more (we will never know what really happened or what Hamilton intended to do). The public wanted to canonize Hamilton. Hamilton did apparently give the same advice to his son (firing into the air) who died in a duel three years before (at least according to Chernow). The younger Hamilton apparently aimed but shot after being struck.