It is more important to know something about the business domain the project will be in and know the methodology to do project management. I would say that from all the project managers that I have met in IT they have never demonstrated that they ever had any tech knowledge worth noticing. Getting on to project mangers in non-IT sectors I personally know 3 project managers that are Chemical Engineers doing project management for civil engineering projects. What helps is domain knowledge and the methodology to do the job. I would agree with the author to try for the job and to back up the experience with a formal qualification.