Errr, no. Roy (in Az., anyway) has the Right to use enough force to detain a person he sees comitting a crime. That includes a third party. The issue then becomes: what IS enough force? Since Roy is an "older gentleman" & I'm assuming the suspect is younger & therefore (a reasonable person would assume)in better physical condition, the issue of "disparity of force" comes in, in which case one has to ask if what he did was reasonable. Given you can't (reasonably) expect an older man to sustain a physical confrontation with a healthier, younger individual, I would say (if I were Roy) the gas-dousing was done to actually intimidate the individual and therefore reasonable and let the Courts decide if I was "reasonable" in my behavior.
My guess is the cops that showed up had a good laugh over it & let Roy go.......