Charging as a liquid into the high side is preferred, but of course the compressor must not be running at the time. What he did is not only just fine, but is standard.

Charging a non-running system into the low side can cause too much fluid to accumulate in the inlet, slugging the compressor.

There is a test fitting for testing the evaporator for leaks. It bolts in place of the expansion valve and lets you pressurize the evaporator with nitrogen. The FSM shows the tool, its use and part number.

And get a better vacuum pump. Unless you're reporting to the tower, 25 inches is not nearly enough vacuum to boil the water out.