I bought a 2008 bmw 1 series last week with an MOT and no advisories. 
 

took it into a garage with it not started and he has found that the sump is rusty/corroded. It has leaked oil and leaked over all the covers too.

should this have been picked up at MOT? 
 

ive attached the pictures

Morning

Welcome to the Forum

Clearly for some years there has been no oil leaking onto the sump or it wouldn't have rusted. Has it come from a part of the country that has used lots of road salt or coastal salt spray perhaps?

With regard to your question about the MOT. In your picture the under guards have been removed to access the engine. For MOT they would be in place so the sump would not be visible, MOT inspectors are not allowed to remove guards to inspect cars/vans so unless an oil leak is obvious (dripping) it won't be reported on the MOT, some inspectors qualify their inspection by commenting that covers were in place.

All that doesn't alter the fact that your sump doesn't look good and me personally I would change it, Doesn't have to be new just in good condition so check Ebay and the specialist BMW breakers.

Dave