Hollywood is like a small town -- everyone knows everyone or at least knows someone who knows someone. So, when you lie on your resume or in a job interview, you’re bound to get caught. There are big, obvious lies to stay away from, like saying you interned at a production company whose doors you never even walked through, but there are also smaller lies that can get you into trouble.
If you were an intern, don’t say you were an assistant; chances are, your future employer knows someone they can call to verify (or worse, knows the actual assistant!). If you were an art department PA, don’t say you assisted the producer. If you spent your summer only writing coverage, don’t claim that you developed projects. The risks of getting caught far outweigh the benefits of stretching the truth.