Under main option B there are specific contract provisions which deal with a change in quantities under clause 60.4., although all of the requirements in the stated bullet points must apply, which doesn't mean that the contract is 're-measurable'. The exception is that a change in quantities which causes 'a delay' is always a compensation event, as stated at clause 60.5..
If items are 'missed' within a quotation assessment then that is a risk which needs to be addressed by the Contractor by the use of assured and consistent contract administration. The Project Manager is not obliged to correct 'mistakes' and his part in this instance is to; accept a quotation, instruct the submission of a revised quotation or to undertake his own assessment, where one of the bullet points under clause 64.1 applies.
Furthermore, it is clear from the case of Costain v Tarmac (2017), that the obligation to 'act in a spirit of mutual trust and cooperation' does not mean doing the other person's job for them.
If items are 'missed' within a quotation assessment then that is a risk which needs to be addressed by the Contractor by the use of assured and consistent contract administration. The Project Manager is not obliged to correct 'mistakes' and his part in this instance is to; accept a quotation, instruct the submission of a revised quotation or to undertake his own assessment, where one of the bullet points under clause 64.1 applies.
Furthermore, it is clear from the case of Costain v Tarmac (2017), that the obligation to 'act in a spirit of mutual trust and cooperation' does not mean doing the other person's job for them.