Yes, if the system is low enough for the low pressure switch to interrupt the clutch circuit it is VIRTUALLY empty, but there is still refrigerant present.

As I recall the Federal Law requires 10" Hg for one minute, or something like that, for it to be considered recovered. In the old days before EPA intervention, we would have simply released what was left, do the repair, evacuate and charge. What would have been released would have been only a few ounces. People do that today, but they are violating Federal Law. If anyone recommends that you violate Federal Law it won't be me.

The fine is something like $10,000 if caught, and the reward to the snitch is several thousand.

Good luck,