I don’t think any laws are being violated...the bounced around microwaves are being produced by energy and the energy being produced is able to be made phase coherent and focused to produce usable thrust. I wonder if he equal/opposite reaction equation is made up for by energy being used/and transferred from microwave to magnetic field energy which is working opposite gravity. We need to get this device into free fall to see if gravity repulsion is the factor in how this drive works or not. If it doesn’t work in space then the factor has to be gravitational repulsion. If gravity repulsion is the key...then we may very well have solved the problem of getting heavy lift vehicles into orbit using small fractions of the energy necessary of traditional chemical rocketry!...but I wouldn’t look for it to power vehicles in free fall to Mars!( it could be used to assist in landings and takes offs...perhaps in slingshot maneuvres around planets...ect!)
My first thought as well upon reading the article. They are just not looking for or measuring the right thing(s).