Reading option B, clause 60.6 “The Project Manager corrects mistakes in the Bill of Quantities which are … due to ambiguities or inconsistencies. Each such correction is a compensation event which may lead to reduced Prices.”
From what you have said, this fits with being an ambiguity or inconsistency. Correcting it would result in one of the descriptions and rates being deleted. I was going to quote clause 60.7, but this only applies to inconsistencies between the BoQ and other documents. In fact, I think the contract is silent on this so we have to revert to contract law.
A general principle of contract law is that a party cannot suffer if the other has made the original mistake, unless specific condition precedents - or contractual hoops to jump through - are stated for the other to claim. E.g In the ECC, this is following the compensation event process and time scales.
None are stated, so we are left I think with three alternatives :
- the Contractor is paid for both rates i.e. £100/m + £200/m = £300/m ! I think this is over-generous to the Contractor and it is not that they are suffering, they would be positively gaining from the error !
- the Contractor is paid the lower rate i.e. £100/m. As a Contractor, I would argue I am suffering, so does not apply.
- the £200/m seems to be the sensible middle ground both commercially and legally.
I will ask one of our lawyer contributors to confirm though.