No. He was 14 when the offence was committed (in 1989). I do not know whether Claire's Law would fit this scenario, nor whether it is retrospective. In addition, the Sex Offenders Register did not come into effect until 1 September 1997 and is also not retrospective.
Source:-
What is the sex offenders register and when will someone be put on it? - claims.co.uk ™.
ETA - Essentially, it would come down to what the charge was and the sentence he would have received as a Juvenille at that time (1989) as to whether he would have still been on the Register. I don't know what the sentencing regime was in the UK in 1989 for those
under 18, but it could have been anything from 10 years to an indefinate period.
A little more information here -
The length of time required to remain on the register is calculated as follows:
- If an individual has been sentenced to life imprisonment; for more than 30 months; or imprisonment and admission to hospital under a restriction order – they will be placed on the sex offenders register indefinitely
- If an individual has been sentenced to imprisonment for more than 6 months but less than 30 months – they will be placed on the sex offenders register for 10 years
- If an individual has been sentenced to imprisonment for 6 months or less – they will be placed on the sex offenders register for 7 years
- If an individual has been cautioned for an offence under the Sexual Offences Act – they will be placed on the sex offenders register for 2 years. If the offender was under 18, they will be placed on the register for 1 year