I know mistakes like this happen. It does happen to me when I'm in a hurry and I just want to stake and move on to something else and come back later to check the results. And yeah, when things like this happen, you know, you have to have emotional control as a gambler. You don't get worked up over it. You just laugh at it and move on and be careful next time. Luckily, you didn't stake a very huge amount, so just be careful with your stake next time, not to stake on simulated reality leagues because it's programmed and your chances of winning are not that much.
Sometimes you just want bet on a club and move to other important task. This mistake is common when when you are placing bets in an uncomfortable environment. In some work places every worker are forbidden to gamble. But some point you horridly place bets during work hours and they might make mistakes since they are doing it with tension or the fear of being caught by supervisors.