Is it legal for an apartment manager to Evict somebody without proof of them doing anything wrong.

My friend had inspection today at his apartment. And the manager walks in doesn't check anything and just says

it stinks in here. I'll be back in a few days, if it still stinks you're Evicted.

You can take pictures of dirt and damage.But To evict someone because you don't like the way their apartment smells? There is no paper trail. No proof of any wrong doing. And on top of that. He is mentally handicapped.
And been found incompetent by multiple psychologist.