The first sentence of the answer states that the Contractor’s qualifications will not become the Project Manager’s assumptions. The second sentence suggests the Contractor’s qualifications are Contractor’s assumptions he has had to make and therefore if they turn out to be incorrect the PM should raise a CE under Clause 60.1(17). That clause would appear to apply only to PM stated assumptions.
Only the Project Manager can state assumptions. By discussing (62.1) with a Contractor different ways of dealing with a compensation event the Contractor may identify assumptions which the PM could include assumptions in his PM Instruction (61.6)
This is a common issue and misconception that if a Contractor includes assumptions within their quotation and the PM accepts the quote that these are deemed to have been accepted. Contractually this is not necessarily the case at all and I ask Contractors where will the be able to claim for this within the Contract. If they stated that they had made no allowance for bad weather, and then bad weather occurs, are they entitled to reassess this? Contractor will obviously believe so but the contract only says it is a CE if it exceeds a weather event in 60.1(13). It also says it is a CE if a Project Managers assumption proves to be incorrect, not a Contractors assumption (60.1.17).
Therefore there are two solutions to this problem. If the Contractor has very sensible assumptions they think allow them to price this event much more sensibly, they can propose them to the Project Manager to confirm them back to the Contractor as his assumptions before they submit the quotation. Alternatively they should simply price the risk within the quote and make it clear why it is so high/what it includes.