re: Mir's hatch in 1990
Soloviov and Balandin went for a EVA to repair their Soyuz. They damaged the hatch (it blew open when the airlock had not been completely depressurized). And when they finished their repair, returned back only to see they couldn't close the hatch anymore.
LUCKILY, they could depressurize Kvant2 from outside.
If there had been a 3 cosmonaut inside, he couldn't have helped them as the airlock was under vacuum and he would have been safely inside.
If they had not been able to get back in, then.......
Raoul