I will not take it as a common loss, I'm gonna put more attention with the player and if he's quite common making mistakes to score own goal, I wouldn't bet on the team where he played anymore.
But you are right, we also have to look at how often he makes mistakes, whether they are mistakes he makes repeatedly or just in that match. Because even famous players can make mistakes, it's just that the mistakes they make are a little different, for a goalkeeper he might make a blunder as we saw in the Liverpool match in the Champions League. Karius at that time made a lot of blunders which ultimately had an impact on his career. For strikers, maybe they cannot take advantage of opportunities, such as penalties for example and many more.
If that player really often makes mistakes, then I, like you, will reconsider betting on that team, for example, when Maguire made mistakes very often in Manchester United's back line, I didn't even think about betting on them. Lol