FWIW do not involve solicitors in this. They simply contribute to the sum
total of human unhappiness. They get paid whether you win or lose ( so what
is their motivation to do well by you? ).

You should also dispense with the idea that a lawyer will be able to
give you a definitive answer as to whether you have any liability. The law
is not a science, it is about adversarial banter, precedent, being able to
wheedle out arcane excuses, and not least, what the personality of the judge
is like.

Make the man an offer but don't let him take you for a ride, i.e.
don't admit liability but make a goodwill gesture, write 'without prejudice'
etc as you have been advised on correspondence. Learn from this and make
sure if you use ink next time you also blot people's hands afterwards and
warn them not to get it on their clothes. It'll be miles cheaper than a
lawyer.

And, no, I'm not a lawyer; I have though, had the misfortune of engaging
several.

Andy ( who knows that British law is the best in the world......that money
can buy....)