actually, Titmus did find and follow the trackway, and cast 10 prints from it. Laverty also saw it, and photographed some of it.
What appears to have happened is that when Patterson and Gimlin manufactured the deep fake trackway (an inch deep, according to Laverty and the casts and photos) probably on October 20, they did not follow PattyBob's route exactly...possibly because MissPattyBob's huge rubber clownshoes didn't make much of an impression in the soil, and because many days had passed since the filming, so it was hard to follow in all parts of the sandbar. This would explain why, although McLaren may have followed the persistent remains of the deep fake trackway 8 months later, his route, as seen on the Green film, doesn't match that taken by PattyBob on the PGF, whose faint traces would have long disappeared.
PattyBob did not make the persistent, obvious, deep trackway; Patterson and Gimlin did.