Once structural problems are found during the home inspection, the inspector will be faced with the decision of whether to recommend a qualified contractor or a structural or soils engineer. The agent and the client may or may not agree with with the inspector's decision.
The advantage to recommending the engineer is that for the inspector, it's safe. The engineer will assume all the liability. For the client, it's safe- the client will get (arguably) the professional most qualified to identify the problem and recommend a solution.
The disadvantages are primarily disadvantages for the client. Good structural engineers are busy and may not be able to respond quickly. They are also expensive and although they may identify the problem, they are most likely to recommend a solution which protects them from liability and cost will probably not be their main consideration.
The advantage to recommending a qualified contractor is that they will often evaluate the problem, issue a recommendation and give you a price for correction... all for free! With an engineer, the client only gets two out of three and pays a lot of money for them.
There are very experienced contractors available who are perfectly qualified to evaluate problems which don't require engineering calculations or whose experience allows them to be comfortable making decisions in situations which might ordinarily require engineering calculations.
The word "qualified" is very important in picking a contractor. This is not a situation in which someone should throw a dart at the yellow pages. Unscrupulous contractors may invent problems where none exist because they want the work or because they don't understand what they're looking at. Homes are complicated collections of systems and components. Unqualified contractors may make recommendations which address the symptoms of a problem, but not the fundamental problem itself.
I routinely recommend a foundation contractor who's been in the same business for 40 years and who has an engineer on his staff.
When I find roof trusses or engineered lumber which have been improperly cut and it appears to me that the alterations were not performed according to engineered drawings, I always recommend a structural engineer.
The final choice in deciding whether to recommend a contractor or engineer will depend on the nature of the problem and the relationships and confidence the inspector, client or agent has with local contractors.