Having had a visit from the enforcement people some years ago I can tell you it's very intimidating. Certainly if I'm accused of sinning again I won't see them without a lawyer present. This has been a complete over reaction to a simple error.
Having "done" this guy maybe they'll now start attacking all the uninsured illegal public transport which goes on under their noses.
Wonder what happened to the chap in a foriegn registered aircraft at Ascot last year....................