I am a lawyer, I'm not licensed in VA and I don't have time to look up their hearsay rules, but I can tell you right now if I were to prosecutor in this case I'd subpoena Gamestop guy for trial a hundred times out of a hundred. I should rephrase what I said earlier a bit; Who you rely need isn't the guy Chris sprayed but the guy that called the cops. It is possible that they'll try and go forward without Gamestop guy and base things off the cop, but I don't think it's wise on the State's part though.
Unless the cop actually saw Chris spray pepper spray in person Chris has at least a non-frivolous argument under Crawford that the person who called the cops has to be available in court to cross examine. The cop could try and testify based off of the video, but there's a risk that the court will buy the argument that the videotape is inadmissible hearsay and the cop's testimony from it is just double hearsay. The risk on the other side is that they'll deem the 911 call and tape nontestimonial, not hearsay, or hearsay within the exceptions of a rule. it largely depends on local rules and hearsay rules are a bit different in practice in every jurisdiction, even if they're the same on paper. (I just looked as I wrote this and there appears to be at least some case law in VA to support the idea that the video is not hearsay, but I don't know how well established the case law is. I'd probably still give it a shot if I were the PD and it went to trial, especially if there's no Va supreme court case on it. The worst thing that can happen is the judge disagrees.)
The right way to think about it isn't like a traffic ticket, but more like domestic violence. When you get a ticket the cop is swearing that her personally saw you commit the offense, that's why he has to show up in court. On the other hand in a DV cas 99 times out of a hundred things have cooled off by the time the cop gets their and even thought the cop arrests you and gives you a summons with his name on it as complainant he isn't the accuser, that's who you allegedly domestic voilenced, he's just the guy who filed the papers. So then, at trial even if the cop shows up if he didn't see you hit anyone the case gets dismissed unless someone who actually saw you do it shows up. The rub here is that there's a video of it happening, but the prosecutor still has to at a minimum authenticate the video and provide foundation for it. He probably can, but you never know. Paperwork gets fucked up all the time