I've heard everything from this will definitely result in the immediate destruction of my compressor to it is no big deal and nothing to worry about. Was a bit low on refrigerant so added some last night. System was running, compressor engaging, but not very cold before adding, and didn't seem to have any problems immediately afterward, but am worried about damage I might have done.
Long story short - the location of the port, height of the can, and length of the hose resulted in the can being closer to upside-down and sideways rather than right-side-up and sideways.
Meh. If it's working I'd say you're fine.
"In Oldskool we trust"