My husband is a new taxi driver but has been suspended after being arrested.?

He been private hire driver for only 3month but 2wk ago was parked up after work cos he was going out for a drink. He told his boss and arranged a lift home afteryards cos it was his birthday and taking 2 days off work. After he left the pub he returned to his car to get his mobile phone which he left so he could ring his boss for the lift home but his battery was dead so he switched engine on to charge his phone. Meanwhile police officer came and arrested him accusing him of driving which he wasnt. He was put in custody and released on bail. Straight away his taxi license was suspended until the court date basicaly but not charged. He is due bail next week and will go to court week later. Is there any way he can do anything to help his case? His solicitor says its 50 50 if his story to be believed. This is his livelihood. And innocent. But the engine was on but only to charge his phone. Any help and advise?