This is not the usual politician's trick of avoiding the question, or answering a different question to the one asked or indeed waffling as to be meaninglessness. Instead the Prime Minister has willingly told a blatant untruth.
Aside from the veto, and Norway's influence duly noted on here and here, it's worth highlighting this - EEA 20 years on, page 18 (my emphasis):
To ensure the functioning of the EEA, the EEA EFTA Member States have to implement all EEA relevant EU legislation. Nevertheless, the EFTA Secretariat has so far identified more than 1 200 EU acts marked as EEA relevant by the European Commission that were contested by experts from the EEA EFTA Member States. An analysis by the Liechtenstein Institute concludes that these rejections were quite consistent with the EEA Agreement because most of these were excluded for technical reasons.I'm aware that keep pointing this out may soon get monotonous, but when journalists like Andrew Marr cannot call out a lie when they see one, despite that as a BBC journalist he knows full well the situation is otherwise, we have to keep going.