Even in ordinary environments password security can put people under that little bit of extra pressure. Mostly it makes no difference, it's just one of those things that have to be done.
The more pressure there is the more problematic it can become.
Sit in a school staffroom at 08:20 and you'll see password sharing, As in, " Oh God it made me change my password yesterday - What the hell was it? X ( insert name) what's your password, I need to print off...... etc....."
Move that into an overstretched hospital department with patients on trolleys and ambulances queuing outside and it isn't surprising if they don't even bother to keep passwords.
It's not just emergencies, it's time pressure. If it takes an extra half minute per patient to change mental gear, ( especially if tired or rushing), recall and enter the password then by the end of the clinical day enough time for a number of slots have been used to type passwords - and that's assuming it works well, there's no need to retype the password and they don't get locked out.