‘The duty to warn arises as no more than an aspect of the duty to act with the skill and care of an ordinarily competent professional. The existence of the duty recognises that in some circumstances the professional must go beyond what is specified as the desired performance in a contract (e.g. carrying out a design) and account for any risks of which he is aware by virtue of that expertise and warn others who may not be so aware.’
Hardwicke Chambers, 19th April 2016
Source: www.hardwicke.co.uk