This is not surprising. I spent 10 years as a patrol deputy at what is now the South L.A. Station and another 7 years as a supervisor at two adjoining stations. I don't know the facts of this particular case, so I can't comment specifically. But as a general rule, the filing DDAs generally defer felony prosecution on gun cases involving generally responsible citizens. That's not just for the politically-connected and sports figures. It's across the board. Most often, the result is a misdemeanor plea bargain with a firearms prohibition. If the probation is completed, everyone wins. If it isn't the the DDA drops the hammer on the second filing.
I hate to agree, but I must, that a lot of deputies are not as familiar with weapons as they should be. The range of laws that we enforce is just too wide to be an expert in everything. I once did a shift briefing on Assault Weapons (as law existed in 2004) and I showed a photo of a tripod-mounted, single shot, Browning M2 chambered in .50 BMG. I asked the shift deputies what they would do if they encountered a person firing this weapon at the range ( the station I was working at had a large range in our service area). Every deputy on duty replied that they would arrest for possession of a .50 BMG Rifle. So followed the on-scene instruction of the elements of that offense. But it's worth noting that SB23 (1999) changed the definition of "Assault Weapon" such that the same M2 would be an illegal Assault Weapon (but still not a rifle) today.
We lost a fair number of Vehicle Search cases when presented for filing. The key issue usually being the articulation of the lawful standing needed to conduct the search. The state of the case law makes it very easy to lawfully search vehicles, but it's not automatic and the burden is on the deputy to sufficiently show their legal standing.
