Is it plain error to admit evidence of a police officer's remote PTSD diagnosis to challenge the officer's credibility and prove he was more likely to have acted unreasonably in his use of force where there is no evidence the officer suffered from or experienced any symptoms of PTSD at the time of the incident?

QUESTIONS PRESENTED 1. Is it plain error to admit evidence of a police officer’s remote PTSD diagnosis to challenge the officer’s credibility and prove he was more likely to have acted unreasonably in his use of force where there is no evidence the officer suffered from or experienced any symptoms of PTSD at the time of the incident? 2. If a suspect has stabbed an officer, been shot and wounded by the officer, dropped his weapon and continued to advance on the officer in a confined and unfamiliar space, all within a matter of seconds, does clearly established law put every reasonable officer on notice that the suspect no longer poses an immediate threat and prohibit the officer from firing a second shot to subdue the suspect?