There is no specific offence of '‘interrupting a drone pilot mid flight’ (or similar).
Article 240 of the Air Navigation Order 2016 does NOT apply to the flying of drones. "A person must not recklessly or negligently act in a manner likely to endanger an aircraft, or any person in an aircraft". That's because 'small unmanned aircraft are exempted from the provisions of Regulation 240 by those of Regulation 23. So distracting a drone operator in a way that results in damage to his drone alone is NOT a criminal offence.
However Regulation 23 does NOT exempt 'small unmanned aircraft' from the provisions of Article 240, which therefore DOES apply to drone operation: "A person must not recklessly or negligently cause or permit an aircraft to endanger any person or property".
So someone who 'recklessly or negligently' distracts a drone operator in a way that subsequently endangers people or property IS guilty of a criminal offence.
Civil liability is, of course, a separate matter. Anyone whose actions result in damage to someone else's property, or to their person, can be required to pay compensation.