If it's done with a good machine, which I would figure your guy has, an evac will tell you how much came out. That way you will know if it was undercharged. If it was undercharged it's good to put it under vacuum for a while and see if it holds. If not, there is a significant leak. It is normal for these to lose some refrigerant over time, so even if it's low there may not be a major leak to be fixed.

__________________
Alex
MB Star certified, now independent.
Owner/Operator FDMotorsport Mpls. MN
Mercedes and GM certified transmission rebuilder
We all need a little help sometimes...

1998 E320 4MATIC-- stolen by my sister
1989 300TE-- sold
1999 C230 Kompressor