Was this situation fair or was the SM unfairly treated?

In context: SM is seeking training on equipment they are already certified for (5~6yrs). Others who are not certified have been using, driving and operating this equipment with the leadership who are in control of this equipment. The leadership and non-certified operators are buddy-buddy. When leadership within the chain of command were confronted about the situation, the certified SM was ignored for 2 years. When an important mission arose, the SM was the only one certified to run the equipment and asked if they were able to recover a vehicle. The SM explained they could, but didn't feel comfortable because the lack of training they have received and the A-driver must be certified as well. All other operators were unavailable at the time. Days pass and the SM was approached and spoken to the their section leader. SM explained the situation, the embarrassment of not knowing their job well enough and the unfairness of the leadership which lead to their current situation.

The information reached the senior leadership and swiftly came back to the SM. The SM was called down to the office where they were spoken (loudly) at, not to, and not listened to as they were causing a commotion among the equipment operators. The leadership exclaimed about the MTOE and slots (not that a lower enlisted would know this as common knowledge unless they researched it or learned from others, nor does it explain the training issues or the non-certified solder issue) didn't want to hear or understand the SM's issues, they also made it clear they will "Never" operate that equipment while they are in charge and that if the SM wants to do so, they need to find another unit...

The SM was then pulled into a meeting with their leadership and one of the leading operators of the equipment. On the way, they stopped by their MRNCO's desk about something else and was asked if all was OK as the RNCO and others were questioning the SM's profile. The profile does not have any restrictions or limitations other than for the APFT. When this second meeting commenced, the breakdown was the SM was "burning bridges, causing issues and breaking the chain of command." The profile was then brought up and they told the choice to not allow the SM to train, use or operate the equipment was based off of the profile which was never explained to them. The SM clarified the profile was set up to allow for the operation of all equipment and vehicles as the unit prior helped clear it years ago for the certifying school. They then said "well, i need people that want to learn and are willing to work" degrading the SM's work ethic and constant curiosity to learn.

As the SM believes they are dealing with toxic leadership and the favoritism or the good ol' boy system is in play, is there a violation of any regulation/rules? Does seniority and qualification supersede a leadership choice like this? As the opportunity to learn, gain experience and better themselves is being put on the back burner and the pursuit of the SM's profile to create a justification are included in this situation, would this be a form of discrimination or EEO issue? Does the side effects on the soldier life, mental health and confidence matter?

Please keep in mind, this unit is already under fire for many other issues and others are dealing with similar situations.

Thank you in advance for reading, I appreciate all guidance.