Often implies events beyond our control have caused the problem, rather than someone's mistake. Missing the crucial penalty kick was a mischance that cost them the game.
Pro Tip 2/3
Not Intentional
Indicates that the unfortunate event was not caused on purpose. His absence at the ceremony was due to a mischance, not a deliberate decision.
Pro Tip 3/3
No Blame
Used when no one is to be blamed or held responsible for the unfortunate event. Despite the costly mischance, no one in the team was at fault.