User blog comment:Uncleho/Perhaps this is how Arthur learns of Merlin's magic?/@comment-5286206-20121118195617

Remember when Arthur called Merlin in. Do you think he already knows Merlin has magic and overheard Merlin enchanting him whilst under that horrific dose of poison. (Morgana overhearing Uther)

I highly doubt this, but I did notice that Arthur spoke strangely. Whether this was solely to do with Merlin undergoing prison charges?