Checking repairs made after inspection negotiation?

[Jordan B.]

Hello BP,

I just had the inspection done on a property I have under contract.  It came back that the chimney is leaking due to improper flashing.  I asked the seller to have the chimney re-flashed before I would close on the property.  He agreed to the repair but now my question is, how do I know if he really made the proper repair or if the repair was made at all? Do I hire a contractor to go look at it before closing to make sure it was done right? Do I ask to get on the roof to take a look to see if it was done correctly?  

Thank you,

Jordan