Professional ethics is taken very seriously by practicing engineers. Not to mention that there are very serious liability consequences for falsifying this sort of thing, taking shortcuts is a good way to end up in prison.
In my Country (Australia) as an Engineer there are potentially very serious legal consequences if I certify something or sign off on work some other engineer has done (like the contractor you suggested in example) without doing appropriate due diligence.
In my workplace an industrial plant, for example before we adjust any safety factors there is at minimum a documented risk assessment process carried out. My work justifying the change will need to be reviewed and signed off by two other engineers.
In my Country (Australia) as an Engineer there are potentially very serious legal consequences if I certify something or sign off on work some other engineer has done (like the contractor you suggested in example) without doing appropriate due diligence.
In my workplace an industrial plant, for example before we adjust any safety factors there is at minimum a documented risk assessment process carried out. My work justifying the change will need to be reviewed and signed off by two other engineers.