http://www.bbc.co.uk/news/uk-43453525
A couple of things caught my eye:
The Metropolitan Police said officers were called to Lower Richmond Road in Mortlake at 15:59 GMT on Sunday.
The ambulance service and London Fire Brigade also attended and a number of people were treated for minor injuries.
Police said a 42-year-old man was arrested at the scene after failing a roadside breathalyser test.
He was taken to a south London police station for questioning before being released under investigation on Monday.
(My emphasis)
In layman's terms, somebody arrested after a breath test can generally be detained until their blood alcohol is below the legal limit.
http://www.legislation.gov.uk/ukpga/1988/52/section/10
Even if it was 0001 this morning, that's eight hours, which is quite a time to blow negative.
As Saturday Night Takeaway is broadcast live, Mr McPartlin is scheduled to be back on air this Saturday. ITV are yet to comment on whether Sunday's events will affect the show.
Innocent till convicted, etc., but this may be something of a dilemma for ITV.