The regulator said the context in which the comments had been made meant the comments themselves were justified and that in fact Clarkson had meant them as a "joke".
In November last year Clarkson appeared on the BBC's 'The One Show' and said striking public sector workers should be 'shot' and that he would take them outside and 'execute them in front of their families'. He also questioned whether the workers were right to strike when they have 'gilt-edged pensions ... while the rest of us have to work for a living'.
Trade union body Unison had claimed that Clarkson's comments were in breach of three rules under Ofcom's Broadcasting Code.
Under the Code broadcasters are obliged to ensure that the public is adequately protected from harmful or offensive material in accordance with "generally accepted standards". Unison said that Clarkson's comments were "extreme and wholly unjustified" and breached the Code rule because members of the public had been "exposed" to harmful and offensive material.
The Code also requires that "material which may cause offence" be justified in the context in which it is broadcast. Unison claimed Clarkson's comments "were liable to cause unjustified offence".
Broadcasters are prohibited, under the terms of the Code, from broadcasting material which "condones or glamorises violent, dangerous or seriously antisocial behaviour and is likely to encourage others to copy such behaviour". The context must also be assessed in determining when such material is justified. Unison had said the BBC had breached this rule because Clarkson's comments "condoned violent behaviour".
However, Ofcom dismissed the complaint (4-page / 2.62MB PDF) despite admitting Clarkson's comments "could be controversial and were potentially offensive to some individuals".
Ofcom assessed how viewers would have perceived Clarkson's comments based on the "editorial nature" of The One Show and Clarkson's frequently-expressed controversial views. It also assessed the context of the conversation in which Clarkson made the comments.
Because The One Show's "editorial nature" was "light" and "is not presented as a serious daily news analysis" and because the presenters had introduced Clarkson's "provactive and outspoken nature" using "light hearted irony", the comments were not unjustified in their context, Ofcom said.
"The editorial content and the editorial nature of the programme as a whole would have prepared viewers for the type of comments Jeremy Clarkson would be likely to make," Ofcom said.
Ofcom also said Clarkson's "well-established public persona" would also have led viewers to expect Clarkson to "make potentially controversial or offensive statements".
Most viewers would also have realised Clarkson was joking and that his comments "were not an expression of seriously held beliefs or views that should be literally interpreted," the regulator said.
Clarkson's 'joke' was also "to a considerable extent" aimed at the BBC's need for balanced coverage, it said. When Clarkson told the presenters he agreed with the strikes on the basis that London's streets were free from traffic he subsequently referred to the need for BBC "balance" before commenting about shooting and executing those on strike.
"This underlined that Jeremy Clarkson was not making his comments in earnest, and that the target of his humour was partly the BBC and its requirement for balance," Ofcom said.
The regulator also said that the fact Clarkson's comments were not made seriously meant the BBC had not condoned or glamourised violence that was likely to encourage others to act it out.
Ofcom's statutory duty to set standards relating to the content and other aspects of broadcasts stems from the UK's Communications Act. Ofcom's Broadcasting Code sets out what broadcasters can and cannot do when producing content. Some parts of the Code govern aspects of the content the BBC produces, whilst commercial broadcasters must abide by the Code in its entirety.
BBC staff must follow specific guidelines on accuracy and impartiality. These rules are set out in the BBC Agreement, which the corporation signed jointly with the Government.
Ofcom can issue commercial broadcasters with fines of up to £250,000 or 5% of their qualifying revenue, whichever is greatest, for breaches of the Broadcasting Code. Ofcom can fine the BBC up to £250,000 for breaches of the Code.