I think one thing worth remembering is until 2000, the age of consent for 'homosexual acts' was still higher at 18, even though it was 16 otherwise. So someone would still be 'underage' in the eyes of the law at 16-17, even though they can consent to sex with the opposite gender. It's also likely the charge wasn't one we'd use today (since it happened before the Sexual Offences Act 2003 was in effect) so they might have just been told he was being investigated for a 'buggery' charge or 'lewd and lascivious behaviour' which wouldn't immediately ring alarms in the way a 'sexual activity with a person under 16' charge would today.
Personally I'm not sure how much the police would actually disclose to an accused's employer though beyond any charges and incident dates.
I've had a justice-related job where we sometimes had to contact police forces regarding cases, and most forces flat-out refuse to answer any questions while enquiries are still ongoing (even when you're just asking to clarify a typo in the date the police already gave, because I don't think it is going to 'jeopardise the case' if you just confirm nobody time travelled to future so I can log the correct date please

).