He was probably mistaken to advertise himself as an engineer without further verbal qualifications or disclaimers to a state board. More interesting would be if he stated his education and experience and said that he is specifically not an iOregon registered (mechanical, civil, electrical, etc) engineer.
Public discussion alone of suggestion of errors, principles, calculations and opinions should clearly not be forestalled by such suppressive action. The fine sounds like a power grab in two directions, both over bland use of "engineer" vs "registered engineer", and criticism over the traffic lights.
* Certainly if he was licensed and practiced in another state, there would be other Constitutionl issues
* Many people have various engineering degrees and work for large organizations with registered discipline engineers carying the stamp
* Much of the work is not in highly regulated areas, or simply involves research, operations, administrative and supervisorial duties
* Much work goes on in new, evolving areas that would overlap disciplines.
Personally I think a lot of the problems with medicine include too broad licensing laws in was that conflict with discovery and progress by outsiders.