Doom All-Ghost effect glitch

During one of my doom 2 nightmare attempts I experienced a very rare glitch in doom, I uploaded this since I assume not too many people know about it and it’s kind of funny. It’s a bit of a combination of everything getting noclip\idclip and not being able to deal or take damage with projectiles\hitscan. This is the glitch named All-ghost effect, in my countless hours of playing doom I’ve only come across this 3 times. No cheats or modifications to doom of any kind are used, the video is made by playing back a demo I recorded, the demo was recorded in a sourceport which is compatible with the original dos version, so everything seen here can happen in the original dos version too. This is also playing on nightmare difficulty, so I can’t use any cheats like IDDQD, IDFA or IDCLIP. Monsters are able to damage me with melee attacks, but not with projectiles or hitscan. When you turn into a ghost you cannot activate switches or teleporters, you can kind of see that I tried to hit the exit switch, but it didn’t