The understanding of 'misapprehension' can depend on the situation. Note what's being misunderstood. He was under the misapprehension that the meeting was postponed, arriving an hour late.
Pro Tip 2/3
Not Deliberate
'Misapprehension' implies a mistake made innocently, not on purpose. Her misapprehension of the rules was accidental, not a deliberate attempt to cheat.
Pro Tip 3/3
Correcting Misapprehensions
Use 'misapprehension' when addressing and correcting someone's false belief or error. To address his misapprehension, the teacher explained the concept again with a new example.