Accessible toilets assessment centre

Accompanied friend to assessment for pip. Friend panicked needed the toilet, h(a bowel condition) left assessment room heading to where (on previous visit there was a w.c)was told by our male assessor NO u got to go out through locked door(down a long corridor)to w.c in reception area. Halfway down the corridor another assessor came out, probably to see what was going on-i said she needs the toilet, 2ndassessor then turned indicating back down the corridor. At this point I noticed our assessor (at the top end of the corridor)put his finger over his lips, as in a SSH and then a wave of his ✋ and head. Female assessor then turned back to us and said "throught door to reception"and then I said, so we have to buzz again, yes was her reply. I was disgusted, didn't say anything as my friend was so stressed. I believe he was informally watching to see how she moved, and she did, as she was panic struck and embarrassed by the questioning.she has led a sheltered life. His report says he assessed her mobility, is there a law saying how many toilets there should be and if they should be within the confines of the "locked"area. I have logged a complaint. Any input appreciated. Sorry so long.