Can this Army Vet still be charged under the UCMJ

A veteran - recently released from active duty who served with the 75 Rangers may recive punishement under the UCMJ, while he was participating at an "Occupy Seattle" protest.

 

Good Point

From Mil.com
d. In accordance with chapter 45, section 771, title 10, United States Code (10 USC 771), no person except a member of the U.S. Army may wear the uniform, or a distinctive part of the uniform of the U.S. Army unless otherwise authorized by law. Additionally, no person except a member of the U.S. Army may wear a uniform, any part of which is similar to a distinctive part of the U.S. Army uniform. This includes the distinctive uniforms and uniform items listed in paragraph 1–12 of this regulation. Paragraph 1–12 goes on to define "Distinctive uniforms and uniform items:"

To read the entire article - click here

 

Any individual who joins the military signs up for eight (8) years. 3-4 years may be active or active reserve - the remainder is in the IRR - Individual Ready Reserve - and my understanding is you must attend one muster per year. So yes, you are still in the military - and subject to the UCMJ, until you receive your discharge.
Most people are under the impression they receive a discharge upon release from active duty - that is not so - at that point you only receive a DD-214. Your discharge (DD Form 256) is not presented until you have no remaining military obligation. One exception is if you re-enlist - you are give a discharge fro your previous term of service.

So, Yes, the young man in question (assuming he is a legitimate vet) is subject to punishment under the UCMJ. Army regs do spell out when and where a Vet may wear the uniform.