bit like a lot of terriers that are owned by men that run foxes to ground with hounds. The majority of them will false mark. Reason being 90% of the time they are brought to a hole there's been a fox ran into it. So when they're brought to a place that's not holding, they automatically think somewhere inside there is someone at home because there always is. Seen a few great dogs in the past like this but as you said faults in the man that has ran the dog on.
Seen it with a dog I bought in, he stopped it after a few weeks