In 90% of firearm disarms the firearm discharges at least once. Fighting unarmed against an armed attacker is extremely dangerous, and you WILL get cut or shot unless incredibly lucky. Defense against knife or gun attackers is limited to only a handful of situations even for seasoned professionals, and even less successful for the every day person. The following three educational videos show individuals with with 30 years of experience, and even for them you will see an eye opening fail rate for common techniques taught in self defense classes and shown in movies.
Not every aspect of these simulations is 100% spot on but it is about as close as you can get without doing it for real and endangering human life and well being. Knowing you will get injured means neutralizing your attacker as quick as possible in order to perform or seek first aid immediately to survive.