Don't lose your head in a broach... Keep hold of the guy!
Never let more than one corner of the spinnaker go in a leeward broach. Either keep the guy and halyard on and dump the sheet or, if you want to drop it, keep the sheet and guy on and dump the halyard. That way one edge will always be stretched tight and it will act like a flag ? otherwise the sail will fill and act as a power kite, dragging you downwind out of control.