Bringing the Problem to the Attention of Others
The previous two comments point to discontinue applying the engineer's stamp. I think the first person to discuss this with is the inspection group leader, and state that much as s/he would like to help, s/he can't apply the stamp to work that s/he has not overseen and let the inspection and let the inspector take it from there. It really is the inspector's problem and the inspector should be given a chance to solve it before involving others.
The inquirer might like to consider in advance what will be his/her response if the inspector asks the engineer to review reports and offers to put the inspector's own stamp on the reports on the engineer's say so.
PE Stamp when QA/QC posted by delfan
PE Stamp when QA/QC posted by welden
The application of the PE Stamp posted by PEengineer
Bringing the Problem to the Attention of Others posted by CarolineWhitbeck