Wouldn't this go under the staked thread "If anyone spots forum errors please post them here" ?
Not that this is much of an error.
Sometimes, as people point out, the server checks the actions slower than a person does their changes, so it may show them more than once. It could also be two Tabs open in a browser, or a person checking on two devices, as someone else pointed out.
Not much I can do about it, though.