More than likely he had trouble restoring your backup, or at least the "exports" part of your backup, which is what usually contains your user names, etc.
There is a Siemens password I know of that you could try, but I'm not going to post it out here in the open and I've been yelled at before for posting my E-mail address so I don't know how to communicate it to you. Sometimes it's a good thing we can't send E-mail on this site, and sometimes it's annoying.
Have you tried asking the tech for the default password? I am guessing you would use login engr and then enter the default password and it will force you to choose a new one. Then you would enter the password you normally use for engr and you should be good to go for the next 2000 years!