Ask VOSA?

As the off side repeater is MISSING from the door mirror it's a fail in my opinion, because that year of vehicle should have one (at this moment in time the online vosa manuals seem to be unavailable so I'll go solo lol..)
The 50% rule you talk of is refering to a light source and not the system. Just because you have 2 out of 3 off side indicators working does not make it a pass and advice on calculations of that's more than 50%
The rfr is if less than 50% of a light source is not working IE half of a LAMP for example the LED side lights on a Fiat if the off side light unit (source) has 10 LED's and only 6 are working thats a P&A so if only 4 are working thats a FAIL as LESS THAN 50% is illuminated.
It's a pity the authors of the manual can't understand it!

I failed a Merc a while ago as the off side repeater built into the off side door mirror had had a bash and 3 off the 4 led's were out IE less than 50% of that light source

I can't remember the wording but nissans used to get round it by having a bump on the outside of the front indicator lamp that showed light out to the side and rear.
The manual has gone from the vosa website so I can't check til Monday

Not checked but doesn't the 50% light source relate to each specific unit, and not as whole as this woman is suggesting.

I think she is getting mixed up with what ever information she has been given.

By the way, The mk5 golf doesn't have a wrap around front indicator unit, or bubbles etc.