I was a teacher and examiner in a different subject.
Our grade boundaries were always calculated using a bell curve. Thus, the grade boundaries fluctuated a little every year. I always explained to students how the grade boundaries were set.
When I was an examiner, the grade boundaries were set before all the papers were marked. Possibly after 75% were marked. Trends could be identified by then. An examiners report is written identifying the good and bad parts of the examination.
On the whole, my students got the grade which they deserved. Students who had worked consistently well tended to do consistently well.
The kids who can do difficult questions deserve to do better than those who can't. That's life.
My students didn't regularly collapse in tears. They didn't abuse the examiners. They didn't have diarrhoea.
I did have a few who shed tears of happiness on results day.
This thread reminds me of a hue and cry about a SATs reading paper a few years ago. That involved hysterical kids and parents too. When the results came out they were normal results.
For the record. The last exam that I failed was my driving test, aged 17. I was devastated; for about an afternoon. I didn't collapse into tears. I didn't have a nervous breakdown. I simply rebooked my test and passed it next time. I thought one of my A levels was difficult - I got an A. Teenagers need to build resilience in order to face the real world.
In all honesty, a lot of these kids shouldn't be going to university. They lack the tenacity and resilience required. It will be a waste of time and money.