He didn't force himself. He laid his hand on the other man's hand and then kissed him rather roughly but not aggressively and undid his trousers, or the other man's trousers.
In that way I feel that the 'pretty policeman' description was fair. It was entrapment. However...
Prosecutions for cottaging still occur. It depends on the level of offence - by which I mean offensiveness to others.
In 1960 maybe there was little way to meet other men (don't know how gay women were supposed to hook up).
These days it's not a problem for gay men to find other men to have sex with but I find outdoor sex, whether hetero or homosexual to be extremely aggressive in some circumstances and think it should still be policed under decency laws.
There's a toilet block 2 minutes' walk away from me which is now key-only for the market traders. It's because it was a well-known cottage and women were hissed at by aggressive gay men for just walking past it on the way home.
I also remember George Michael getting nicked for indecency on Hampstead Heath and bleating that it was his culture. WTF?
I don't want to come across the detritus of sex or people going at it while out for a stroll in the park with my kids.