You don't HAVE to do anything. Especially when the claim is ridiculous. Put out a simple, consice statement of what you did with no apology. It is not like the shirt had FAG written across it. PETA, GLAD and all of these other organizations only chime in when they will not likely have a dissenting voice. The more people apologize the more it becomes acceptable.
ickle: + :smiley_ahh: = :smiley_brancard: