 Whether destruction or damage has occurred is an issue of fact and degree in each case and case law suggests that damage must be more than de minimis . In A ( a juvenile ) v. R ( 1978 ) , the defendant spat on a police officer 's raincoat , which was easily wiped clean ; it was held that this did not amount to damage within the 1971 Act . Similarly , in Morphitis v. Salmon ( 1990 ) , a scratch to a scaffolding pole did not affect its value or usefulness and thus damage had not been proved . The court said : 
