Actual differential diagnostic workups to rule in/out PTSD in the VA system are unbelievably variable in terms of their detail, validity/reliability and their quality. Basic stuff like doing a military/trauma history, verifying at least one Criterion A stressor, doing a detailed clinical interview around ostensible trauma- and stressor-related disorder sxs (and their connection to traumatic events vs. other causes and comorbidities), establishing functional impairment, onset of symptoms, etc, is almost NEVER done/documented at VA.
Usually it's people slinging PCL-5s (if that) and using 'begging the question' and 'arguments from authority': "I'm a provider and Mr. X CLEARLY has PTSD." Not even kidding.
The fundamental organizational pathology/issue is, of course the reward/punishment (incentive) structure. There is every incentive in the world to either ignore the issue or be a PTSD diagnosis "rubber stamper" while there is every disincentive to conduct a thorough, accurate, multi-modal differential diagnostic eval process that may result in actually ruling out PTSD and upsetting a veteran. The iron-clad but almost never-spoken-aloud 'rule' that you NEVER question a PTSD dx (no matter how flimsily supported) if the veteran has been service-connected for PTSD results in PTSD specialty clinics being 'haunted' for decades by treatment resistant/immune cases of "PTSD" whose sx self-reports are only worsened by trials of PE/CPT/EMDR/meds/residential stays, etc. At least until that 90% total s/c becomes a 100% P&T or TDIU with some caregiver support or aid and attendance on the side. And now, most of the PCT intakes are recently retired veterans in their late 60s and early 70s who are presenting with requests to be evaluated for PTSD right after retirement from a stellar career at the sheriff's office or fire department. I'd wager that half the local sheriff's departments are 70%+ s/c for disability, most of that being due to PTSD/MH.
I am convinced that the sickness runs too deep in the organization to ever change, short of complete collapse and privatization. I am not advocating privatization, but VA isn't going to change. 'Leaders' will watch the system collapse before they will exhibit the courage to call for accurate PTSD assessments or condone saying 'no' on occasion to a veteran. Disability compensation is going to get so out of control (there is no governor on the system right now) and 'leadership' will keep cannibalizing full time provider positions (idiotically) to help their cronies out (hooking their buddies up with those sweet, sweet GS13/14 non-clinical non-caseload-having expertologist and excellentologist positions) until access becomes so problematic and the remaining providers retire/quit that the system will grind to a halt. What happens then is anyone's guess.