Here you go, send this via the council website and keep a screenshot of the confirmation screen:
Dear London Borough of Lambeth,
I challenge liability for PCN LJ25749846 because the alleged contravention did not occur, this is because my vehicle cleared the priority area while there were no oncoming vehicles within the priority area.
Further to this, the notice mis-states the time-period mandated by paragraph 5(2)(a) of Schedule 1 to the London Local Authorities and Transport for London Act 2003, this should be 28 days from the date of service of the notice rather than 28 days from the date of the notice.
It follows that the penalty charge must be cancelled.
Yours faithfully,