Was it technically a forced discharge? No, of course not. Was it in effect a forced discharge? I'd say yes. Relieved for cause and an Article 15 for assault kills the career of an O-5. He would not receive another command for a long time, if ever, and would have no chance of promotion until after 1 or 2 successful commands and slim chance afterwards. An E-3 can get forgiveness for a minor drug charge (especially in 1981 when the Army was very busy dealing with serious drug problems), but it's completely different with a field grade officer.
His career was effectively over and retirement as soon as possible was in all ways preferable to trying to continue service. So literally forced out? No. Left with no better options than retirement? Yes.
Back in '81, if they gigged everybody for future advancement for minor weed infractions, there would not have been much of a military..........I tested clean, therefore there was no evidence of actual use. I was allowed to speak to JAG before going before our Battalion CO. He reccomended just admitting to the seeds on the floor. It was in no way an admission of use, and the clean test provided no evidence of use. I asked if it would effect future promotions or opportunities, and he stated no. All other factors of my service would negate the minor charge. Too include the amount of money the ARMY had already spent on my training to that point, I.E, Basic, Infantry, Airborne, etc........Had I tested positive, I would have most likely been sent to drug diversion. After completion of dd, it would have most likely not affected any future promotions or advancements either.
On the point of West, he wasn't forced to retire. He could have elected to stay in and resume his career. Whether any future advacemants would be warranted, would be up to high command.......So, Zona's repeated assertions that he was forced to retire is completely bogus.