The former deputy speaker was on Thursday cleared of a string of alleged sex offences - including one allegation of rape - by a jury at Preston Crown Court.
But one of his accusers has claimed parliamentary authorities are ignoring a widespread problem at Westminster.
"I don't think any of the main parties know what to do. The strange [thing] about Parliament is that they make the laws but they don't act like any other place of business," the man, who has not been named, told BBC2's Newsnight.
"Researchers and MPs' staff don't even have an HR department. Our bosses are technically self-employed. Even though we work in one big building together there was no mechanism to deal with this problem. There still isn't.
"They [the parties] were certainly aware that there are MPs and young, twenty-something researchers who are vulnerable because they fear for their careers and all the hard work that they do could just be thrown away in an instant. I think that a lot of senior people count on that - that it can be brushed under the carpet."
He said some young researchers might enjoy the contact but others did not, adding: "They just want to work. They got into politics because they want to change the world, but they find that when they get there they've got to put up with a lot of stuff."
The man said he was "really angry" at the verdict, describing his experience in the witness box as difficult and degrading.
"I've lost everything in this last year and had to slowly rebuild my life. I had ambitions for a political career. I don't see that as a real possibility any more."
But another alleged victim in the trial told ITV news after the verdict that he didn't think Mr Evans should have been charged.
The man said: "I don't think it was a criminal act. It's the sort of thing that happens in every bar. It wasn't a big deal."
Other young parliamentary workers have described a culture where MPs regularly drink with staff in the building, creating the possibility of compromising situations. One of the witnesses in the Evans case, who said he did not see himself as the victim of a criminal act, told a newspaper there could be a "curfew" in parliamentary bars to reduce the possibility of inappropriate behaviour.
He said: "MPs are working away from home for three or four days at a time. You add to that the late nights, the drinks, the general sense of power and you can easily see a lot of people crossing over that line."