Oh 100% you're right.

I'd wager this wasn't one of their first tests (and maybe not even a test at all). Looks to me like an advertisement/publicity stunt/demonstration.

I could be easily wrong since I haven't researched this exact event, but I think it's safe to assume it's more than just a test since they have cameras out.

Even if it does work being shot hurts like hell. Just test it on things that don't feel pain a measure it? You could also totally die from internal bleeding even if the bullet was stopped by a vest.