I used my phone a lot. My role required co-ordinating police resources on the ground. Often the radio didn't work and the handsfree was crap. Those were genuine life and death matters though even I wasn't on blues & twos. Each cop now knows it is their personal responsibility to prove the use. If you can't, there isn't a magic get out of jail free card for cops. Certainly, you are more likely to be done- twice; once by the police/courts and then again by the police discipline.