Richard Hammond Meets Evel Knievel BBC2, 9pm
Emmerdale ITV1, 7pm
Coronation Street ITV1, 7.30pm

He's a much-loved TV presence, perky wee Dickie "The Hamster" Hammond. A meek Stan Laurel to Jeremy "The Boar" Clarkson's overbearing Oliver Hardy on Top Gear. Recall how a saddened nation wept in the wake of his near-death experience in yon high-speed rocket-car crash last year.

It was thus hellish to witness grievous damage being done to the Hamster's cuddly reputation by the ill-advised documentary farrago that was Richard Hammond Meets Evel Knievel. On a conceptual level, things began badly when Hammond described his boyhood hero, the all-American motorsikkle daredevil, as "Elvis on wheels."

Wrong. It would be more accurate to describe the recently-deceased Evel as Colonel Tom Parker on wheels. Elvis's manager began his showbiz career operating a fairground show wherein he encouraged chickens to "dance" by putting them on a heated griddle. Likewise, Evel Knievel was a bike-borne huckster, a sleight-of-hand showman, a dazzler of backwoods rubes. Sure, he displayed a commendable macho bravery in persisting in being flung from a motorbike for a living, repeatedly breaking bones in the process.

Such bone-headed bravery explained the touching nature of Hammond's moist-eyed reverence on first meeting the man he'd idolised as a six-year-old. But what was it one of Knievel's ex-bodyguards told Hammond, explaining his resignation? During his erstwhile boss's public appearances, he'd found himself "in compromising positions - defending the guy that's starting the trouble."

Then, around 30 minutes into the programme, Hammond reminded us of something his adult self must have known when the programme was at the planning stage: in 1977, Evel Knievel, aided by an associate, attacked his ex-publicist with a baseball bat, breaking his arm, for publishing a scandalous biography that he'd earlier approved.

Is it possible to revere someone who does that to another human being (it resulted in a six-month jail sentence)?

Then again, Hammond's brand of worship was oddly punitive. It was painfully obvious that Evel Knievel was gravely ill, breathing through a portable oxygen supply, yet Hammond pursued the dying man through the streets of his shabby home town, Butte, Montana.

This reached its nadir when, mid-grilling, Knievel lapsed into semi-consciousness, and descended to a sub-nadir in a slow-moving golf cart chase.

"I'm chasing an old frail man, driven by a wife half his age, across a golf course," Hammond mock-agonised. Duelling Banjos played in the background. Jeremy Clarkson would have used the Benny Hill theme music. It would have been more honest.

Meanwhile, sizzling storylines presage a traditional Christmas Day feast of drama in ITV1's two big soaps, Corrie and Emmy. As ever, Emmerdale has things crucially a-gley. In rural Yorkshire, you see, there's a foul conjunction of bugs. Not only are the village's home computers being infected by a malicious virus, but its nauseous residents are dropping like flies, poisoned by Shadrach Dingle's dodgy meat. Emmerdale's panto, Cinderbella, has had its cast ravaged by sickness and diarrhoea. Viewers will surely require strong stomachs for tomorrow evening's denouement.

In contrast, Coronation Street does its usual excellent job, focusing on hearts and minds, not bowels and alimentary canals. At Liz's hen night, the gals' thrillsome anticipation of Commando Sam, the male stripper, was undermined by the everyday reality of Weatherfield's blokes. Gormless Vernon, Liz's intended: he's a no-user, isn't he? And no good will come of Rosie the schoolgirl slapper's forbidden passion for pudding-faced John, the teacher who'll never learn. Coronation Street: it never betrays its audience.