I'm no expert, but I suspect that a pattern of lashing out against opponents during in a high stakes business dispute would not typically be considered clinically significant on its own. I don't know how you or others in this thread are intending to use terms like "mental illness" or "mental health issues," but generally I don't think they're appropriate unless you're talking about problems where there's evidence of an underlying dysfunction and no other obvious immediate cause (like exhaustion). Of course, some may argue it's not appropriate to diagnose public figures either way.