The little window on this kind of thing afforded by the MSM, seems to bear that out. The cop, statistically speaking, won't be slapped as hard for a mishap as will a honest-but-careless nonpolice gun owner. The latter is much more likely to find himself or herself a non-gun owner in short order. Police unions might have some role in this "comedy."
I cannot speak for other parts of the country, but what I have seen with the police in our county, you are absolutely right. Just to give an example, a few years ago, two of our deputies were caught by a Missouri Hiway Patrol, drag racing two new county cop cars down U.S. Hwy 71. I kid ya not! Their punishment? 2 weeks suspension WITH PAY.
I am sick of seeing public servants, from cops all the way up to presidents who commit perjury before a grand jury, getting off for what you or I would go to jail for. Public servants, due to their position, should be held to a HIGHER level of accountability, and should have DOUBLE the sentence the common citizen would incur. This cop should pay a greater penalty than a civilian, since as a trained professional he should KNOW BETTER.