The bit about the policeman turned out to be the icing on the cake - the information arrived too late to be any use. The cake itself was an attack on the law for its conservative, cronyist ways: confronted by evidence of wrongdoing by one of their own, the hidebound appeal judges clicked their tongues and gave Kavanagh a hard time.
At the same time, a subplot had Kavanagh's lovable old head of chambers, Peter Foxcott, retiring and desperate to anoint a reluctant Kavanagh as his successor, instead of the irritating Jeremy Aldermarten: Aldermarten, you gathered, was younger, and a moderniser. But what was youth and modernity next to the fact that Kavanagh was a barrister of the old school, more concerned with justice than bills, one who would set the right "tone" for chambers? The episode ended with Foxcott and Kavanagh fly-fishing, and congratulating one another on their decency. Do we scent the merest whiff of conservatism and cronyism here? We surely do.
Leaving aside its deeply confused politics, Kavanagh QC had some good things to offer. There was a lovely moment of bathos when the bent copper's widow chased away an ex- detective by throwing a plate of biscuits over him. There was also Paul Shane's performance as the ex-detective. After years of proving that fat men aren't necessarily funny, he finally used the bulldog set of his mouth to good effect, showing that they can be pathetic and menacing at the same time.
Internal Affairs (BBC2) has been looking at less dramatic aspects of law enforcement - this week, the Environment Agency, an organisation with fabulously broad responsibilities, from flood control to enforcement of pollution regulations, and fabulously narrow constraints of budget and public consent. Inspectors were seen nagging farmers to look after their slurries, investigating vets after clinical waste had turned up in a household-waste disposal site, and inspecting a factory that wanted to burn tyres for fuel. Mark Savage's programme did its best to bring out the black- and-white conflicts - the agency is forever trapped between the aims of industry and the desires of the ordinary public - but what emerged was a grey picture of compromise and slow wrangling. Gripping stuff in its way, but I don't think it will be the stuff of primetime drama for a while yet.