The Zen master pushes the student into specific experiences. When the student gives a specific response, the master knows the appropriate experience has occurred. Experiences can be repeatable. This in some sense can be thought of as religious data. Both science and religion make truth claims, but in the modern world, scientific truth claims are taken to be stronger.
Science clearly works.
The results of scientific achievement are all around, while religion's effects are perhaps more subtle. Perhaps fanatics in all forms of religion give religion a bad name.