The only "wrong side of the sail" situations I can think of are the accidental jibe, and backwinding the jib.
Accidental jibe:
The wind is to your stern starboard quarter so your main and jib are way out to the port side. Then either the wind shifts a bit to port, or the boat heading veers a bit to port, such that suddenly the wind is to your stern port quarter. This can "backfill" the sails, causing the boom to violently swing over to starboard.
backwinding the jib
The wind is to your bow starboard quarter, sails are close hauled in on the port side, and your sailing as tightly into the wind as the boat allows. Then either the wind shifts a bit to port, or the boat heading veers a bit to starboard, such that your jib backfills on the port side. This causes the bow to swing to starboard, forcing the boat to come about.
Both these situations can be dangerous, as they result in quick and unintended direction changes. The jibe situation can be very dangerous, especially in a stiff breeze, as that violent swinging of the boom can injure crew.