Mike - not quite sure what you mean by warranted or unwarranted. Site Information describes the existing site and its surroundings and is used to help you consider your working methods on which you base your price. If Site Information turns out to be incorrect then this could lead to a compensation event under 60.1(12), where you experience conditions it would have been reasonable not to expect.
Site Information is not Works Information. You are to provide the Works in accordance with the Works Information, taking into account the existing conditions that are identified in the Site Information.
If something has been included in Site Information rather than Works Information the Project Manager may need to give an instruction to change the Works information - which would be a compensation event under clause 60.1(1).
In judging physical conditions for the purpose of assessing compensation events the Contractor is assumed to have taken into account the Site Information., publicly available information referrred to in the Site Information, information avaialble from a visual inspection of the Site and other information which an experienced contractor could reasonably be expected to have or to obtain. So if you were working on the site of a redundant factory it would not be unreasonable to expect to come across redundant pipes and services even if they were not shown in the Site Information. Some Employers do add additional conditions of contract “Z” clauses in which they state that the Employer does not warrant, the completeness, accuracy, etc of the Site Information.
There is no defined wording in NEC3 regarding who takes responsibility for the Site Information. As previously stated, there is a mechanism for dealing with any inconsistencies or ambiguities when assessing a ‘physical condition’ CE, although this does not deal with who is responsible for any inaccuracies or misleading information. The latter is effectively a misrepresentation and would be covered by the 1967 Act of the same name. Often an Employer will add wording to the conditions of contract either to limit or to even exclude any liability for the Site Information, which gets round any issues of misrepresentation.