I was mortified that I only realized I had  forgotten to bring poop bags after the dog pooped
How did you react when you realized you forgot a bag?
I almost had a heart attack and then I was like, "oh god. Oh no!"
If you're on a walk and realize you forgot to bring a poop bag, don't ignore the "pick up dog poop" sign. Bury your dog poop instead of leaving it to be stepped in.
I wish I could have done something about it, but I didn't have a shovel either.
I'm glad to hear that you understand the need to clean up behind the dog. Maybe try tying some bags to his leash, so this doesn't happen again.