I am a manager involved in getting project out the door quickly, and oversee several dozen engineers for this project. A year ago, my senior engineer designed a replacement technology for a core piece of technology we use, and almost all engineers opposed it because they are lazy, and some went far as writing lengthy discussions on re-writing this because it was, in their opinion, "fundamentally broken".
One engineer decided to go over my senior engineer and myself to raise her concerns to senior management, and assembled a meeting with other senior engineers. I believe this individual orchestrated opposition to our replacement technology in advance, so that when a larger meeting with senior management and senior engineering took place, there was massive opposition to our replacement technology already.
Regardless of the outcome of the meeting, this engineer went over two senior colleagues, setting us back almost ten months of work, since management now wants us to re-do our replacement technology. Are there any legal problems with firing this engineer?