Do they have a hand signal for chucking your bottle after it's empty on a charity ride? Something like: Hold up empty bottle, shake it to signal it is without useful fluid, make a football long pass movement with your arm and then just let it fall just behind your back wheel to the peril of every rider behind you?
The other hand signal they should make is "Oops, I just dropped my full bottle because I don't know how to remove a bottle from the cage while pedaling..." It goes like this: Drop bottle while fumbling it out of the cage, look back and wobble around on your bike yelling anything unimportant EXCEPT "Dropped Bottle."