Pulling a Dean

To feign surprise or question something where it is glaringly obvious that what is being said cannot be construed in any other way. The person 'pulling a Dean" does so when a minuscule error in wording gives him/her the justification for questioning what is obvious to 99.99% of the population.

Oh my hat! I have to tell you about the time Craig was pulling a Dean. The other day I told him that my car was running low on diesel and that we needed to pull into a petrol station. And he said to me 'oh but I thought you needed diesel?"