Insurance assessment
When an accident of this magniture happens representatives of the various insured interests will be amongst the first people on the spot. They will usually be independent surveyors, practical people from the industry, with accident investigation experience. They won't stick around for the final details, just long enough to get a good idea in their own minds as to what happened, why, and to what extent the underwriters they are working for are exposed. As much as anybody else, they want to know the truth and their job is to get as precise a picture as possible back to their principals, the cargo or hull underwriters, via an assessment.
The assessment isn't binding, isn't valid in a court of law, isn't necessarily a reflection of what the accident investigation team will come up with. But it's likely to be a decent professional analysis of what happened and of where liability, if any, will rest.
If someone in Spain has seen the assessment it might be reasonable to suspect it was prepared on behalf of cargo interests, since at least a large proportion if not all of the cargo was destined to Spain and could well have been covered there. If so, the surveyor(s) would have been primarily concerned with ensuring there was no evidence of under-declaring cargo weight.
This is all quite natural and expected when an accident happens and insurance has to be paid out. It would be grossly negligent for an insurer not to send someone to check out all the potential liabilities.
Having said that, if in fact the assessment is on behalf of cargo, the surveyor is more likely to have been someone very conversant with cargo, i.e. an experienced loadmaster. And his brief will be to verify that cargo was weighed, loaded, stowed etc correctly. He may have views, facts and even opinions as to the cause of the accident, formed from the inevitable contact with the accident investigation team and with surveyors representing the hull insurers, but if he's at all professional, they're not likely to be expressed in an assessment unless they are indisputable and certain to be included in the final accident report.