Can anyone with older children with ADD (or spouses) relate to this work situation?

My 21 year old son has just walked off his new job today.  I am sick!!  It took so long to finally land the job and he was hired out of 200 others.  The job was going to pay him 9.00/hr (a big deal when most only pay 8.00/hr) and it was going to give him a good amount of hours.  He worked yesterday just fine but today his manager said he needed to be doing something differently and, of course, he took it personally with his low self-esteem and it all went downhill from there.  This is the second job it has happened on.  Is there anyone else out there that has experienced this?  I am getting him into counseling so he can hopefully get some help with these reactions.  Any other comments?  Thank you.