What did you do wrong?
IMHO, absolutely nothing.
What did you do right?
To paraphrase something I heard from another person, who was quoting a Stephen King book, you did not worry about the weapons you had--or did not have. You remembered the weapon that you
are..
In other words, you rushed to the sound of trouble and took action. Lesser men than you might try to pick you apart, but you are the one who took action to help someone in desperate need.
You, sir, will do to ride the river with. My hat's off to you.