Nobody says 'break a leg' after a performance.
Under the Uniforms Act of 1894 it is a crime for civilians to impersonate military personnel.
No robotics lab would allow its employees to have beverages on their desk next to computer keyboards.
Dancers don't rehearse in high heels in padded floormats.
The cat comes indoors using a cat flap in a rainstorm but its fur is completely dry.
If the all-important photo was taken with a film camera, there would also be a negative, and if it was printed from a digital photo, there could be any number of digital copies, so recovering the physical photograph in no way assured that the perpetrator wouldn't be found out.