If you lurk here enough you should have an idea of what the general community thinks about personal trainers.
The general consensus is that they are ill educated and often moronic, with some exceptions.
With that said, tell him to piss off.
The ballistic movement on the smith machine is the one where you throw the weight up and actually release your hands on the bar, and subsequently catch it right?
If so, then a smith machine is the only place one could accomplish that. The smith isn't completely worthless, you just shouldn't be doing everything on it.