CNN has done an article on this angle, apparently his commitment to a mental facility was not involuntary and therefore he wasn't technically
committed.
The Virginia State Police Web site features a 16-question "Firearms Purchase Eligibility Test." The site says that answering yes to any of the
queries means a person may not be able to purchase a firearm.
Question 9 states: Have you ever been adjudicated legally incompetent, mentally incapacitated, or been involuntarily committed to a mental
institution?
Because Cho was not involuntarily committed to a mental institution, his appearance before the judge and his evaluation at a mental health facility
did not show up when he bought the guns.
Special Justice Paul M. Barnett, who filled out the certification and order for involuntary admission to a mental health facility, checked the box
that said: "The alternatives to involuntary hospitalization and treatment were investigated and deemed suitable."
"Only if I order them into a hospital is there any effect on their gun rights," Barnett told CNN on Wednesday.
CNN Article
I'm not at all familiar with Virginia law but it seems that the judge has the option to "refer" someone to a mental health facility instead of
ordering it. Since he was "referred" it isn't consider a "commitment" and doesn't show up when they do a background check for gun purchases.
My gut guess would be the reason they allow this is a budge purpose .. if the judge requires them to be committed I imagine the state has to reimburse
the mental facility for their cost.
I'm surprised a judge is involved at all. Here in California if the peace officer feels someone is a danger to themselves/others they can order a 72
hour hold for evaluation ... of course the mental facility can let them go 5 hours later if they feel they are no longer a danger.