i honestly think that valve shouldnt fix this
On one hand, the box is good at confusion and deception, on the other hand, Engineers will have to constantly tend to their sentry's ammunition if a Spy is being a decoy to drain the sentry's ammo
Now, you could say that the Engineer could just pull out their primary or secondary weapon and shoot the Spy, but how many players will actually think of doing that? Think of all the Engineers that try to constantly wrench their buildings if they're being sapped rather than hunt down the Spy, now those Engineers have more problems to deal with
So i do actually like this, but from a Spy's perspective, as an Engineer, this is bothersome, but easy to deal with unless you're the kind of Engineer that just whacks away at their buildings instead of searching for the Spy