One could argue your dad did a badly run Constructional Aggression Treatment (CAT), authored by Kellie
Snider and Dr. Jesus Rosales-Ruiz. I'm skeptical of it, but I do think it has its values when facing unconventional dogs. But I do urge you to read the proper author(s) works.
Just because you can get away with something doesn't mean you ought. Personally, I'd try to focus his attention on me while moving forward. If we can, take a side route. But I've used spinning in a circle with a short leash and jogging before. So, for example, if we need to go towards something he is keying in on, we're gonna jog and play a jog-heel-jog game. If we are at a corner yard with another example, for experience, while we do it whenever the attention wanders, we're suddenly doing tight spins. But that is me.
He seems to key in visually. Is hearing part of it? But either way, how about practicing for success, getting him in "the groove" with something less stimulating?
He's not for everyone, but Zak George's video series "reality dog training" can make you feel better--that even pros can have challenges and make mistakes.
And the name I couldn't remember from earlier is Julie Andrews.