It would really depend on the retailer. Some are very good at exchanging within 14/28 day period. Others will stick to Panasonic's definition of a faulty panel - I think that one stuck pixel wouldn't be deemed faulty.
You going to have to ask the retailer and see what happens. Another alternative is trying a stuck pixel fixer. If you can connect a pc/laptop to your panel you could try this. It requires quicktime.