Official Quakewiki Video - Quake - E2M6 - the Dismal Oubliette (Deathmatch)
Yes, the starting room is impossible to access without a well aimed rocket jump. I am unsure if this room was even intended to be accessed, or if the bar was accidentally not given a way to be lowered. Similarly, it is impossible to get to the Rune room. No Nailgun or Double-Barrelled Shotgun can be found here.