One has tripped the other accidentally on purpose and now the other howls as if singed with fire.

NEWYORKER: M&M World

After all, those who constantly talk of war sometimes trigger it, accidentally or on purpose.

ECONOMIST: A hundred years of bombast

At the hearing, Mr Webb said he had a can of petrol and firelighters in the vehicle but denied starting a fire accidentally or on purpose.

BBC: Isobel Dobson's stepfather 'probably started' fire

And while most applications have default folders where the files they create (such as the Excel spreadsheet mentioned above) are saved, the path to such a folder may have been changed (by you or another user, either accidentally or on purpose).

CNN: How do I retrieve a lost file?

But why, you ask, would Beijing ostensibly back Obama while accidentally-on-purpose boosting Romney?

FORBES: Beijing's Big Fat Judas Kiss for Barack Obama

It can escape accidentally, through broken pipes, valves or other equipment, or be let out on purpose, when it is vented or not fully burnt during flaring.

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