Carl had managed to escape being murdered by the twisted killer and gave testimony in court, however the defence attempted to discredit him by using his homosexuality.
The barrister brought up Carl's previous relationships and "devious homosexual encounters", saying that what happened with Nilsen was just a "sex act gone wrong".
Viewers were horrified by the treatment of Carl and took to Twitter to air their views.
One said: "The homophobia back then was absolutely shocking – absolute p**** of a defence lawyer."
Another raged: "Who the f*** would be a defence lawyer?"
A third wrote: "Convinced the defence lawyer and everyone else wouldn't have tried to make the victim the perpetrator if he was straight."
Someone else tweeted: "I want to punch that defence lawyer so much right now."
And a fifth added: "The defence lawyer is just as bad as Dennis."
Carl, who was aged 21 in May 1982, met Nilsen, who invited him back to his for a drink.
Twisted Nilsen tried to strangle drag artist Carl using a zip from his sleeping bag.
Carl fell unconscious and, terrifyingly, woke up to find himself being held underwater.
Back in 2010, Carl spoke of the attack with The Sun and said: "When he attacked me I was jolted awake to find the zip tightly wrapped around my neck.
"I presumed I'd become tangled in my sleep but Nilsen was behind me, kneeing me in the back and telling me to keep still."
He continued: "No air was going into my lungs and all I could feel was the teeth of the zip digging into my neck as he pulled it tighter.
"I briefly felt blood from the wound trickling over my skin and then I passed out."
In the dramatisation of the trial, Carl was played by actor Laurie Kynaston.