How much did he eat? Testing it out is fine as long as he doesn't eat it every day.
And are you sure he was swallowing and not just picking it up and dropping for the hens to see?
Some of our roos like to show *everything* to the ladies, tidbiting over grit... even so far as when I tip a water bucket out, "Ooh, mud! Honeybuns, look I found mud! I'M the only guy with mud around here!"