Hi Alex! That's a great question, I think the argument could be made for giving at most two people a shoutout on the same day if there is no way to decide between the two. Also, there could also be an "honorable mention" where a slightly lesser recognition could do the trick. I'm a fan of the second one, because we don't want to steal the thunder away from the winner.
I understand your concern about people's feelings should they not win, but this award is given daily, giving them another opportunity to win as soon as the next day. Additionally, this award is not meant to call out all other employees as showing inferior effort; there is no ranking system. It is simply meant to recognize the person who went above and beyond for that particular day or shift.