MOT passed 1 Advisory but ...

[water01]

OK passed the MOT but got one advisory and that is to quote "Nearside front upper (front joint) Ball joint has very slight play".

When I talked to the MOT guy he said keep an eye on it and if starts to rattle it will need changing. But what worries me on the back of the advisory it says "Continued use of the vehicle (even though a test certificate may have been issued), may make you, and/or anyone who drives the vehicle liable for prosecution or invalidate your vehicle insurance".

So have I passed and can use the vehicle and get it fixed when it is more of a problem, or must I get it fixed immediately and not use the vehicle? The whole thing is completely contradictory and doesn't make sense!!