In case you need to remind the police of the law - relevant HC extracts below. Firstly, the road wasn't clear. The second point, your speed, then becomes irrelevant in any case. As others have mentioned, the getting-out-of-the-car bit confirms that this is a person who shouldn't be allowed to drive....
Highway Code rules
165
You MUST NOT overtake
* if you would have to cross or straddle double white lines with a solid line nearest to you (but see Rule 129)
* if you would have to enter an area designed to divide traffic, if it is surrounded by a solid white line
* the nearest vehicle to a pedestrian crossing, especially when it has stopped to let pedestrians cross
* if you would have to enter a lane reserved for buses, trams or cycles during its hours of operation
* after a ‘No Overtaking’ sign and until you pass a sign cancelling the restriction
[Laws RTA 1988 sect 36, TSRGD regs 10, 22, 23 & 24, ZPPPCRGD reg 24]
http://www.direct.gov.uk/en/TravelAndTransport/Highwaycode/DG_070314
129
Double white lines where the line nearest you is solid. This means you MUST NOT cross or straddle it unless it is safe and you need to enter adjoining premises or a side road. You may cross the line if necessary, provided the road is clear, to pass a stationary vehicle, or overtake a pedal cycle, horse or road maintenance vehicle, if they are travelling at 10 mph (16 km/h) or less.
[Laws RTA 1988 sect 36 & TSRGD regs 10 & 26]
http://www.direct.gov.uk/en/TravelAndTransport/Highwaycode/DG_070306