It is possible to have your medical assessment with ATOS recorded but you have to contact them to arrange this. This is from the ATOS ESA Hand book section 4
"The DWP never requires that a medical assessment for advising on entitlement to
state sickness or disability benefits be recorded.
A claimant may request that their assessment is audio recorded. Dual CD recording
machines are available to provide audio recordings. For any requests made by
claimants for their assessment to be audio recorded, the resource team at the MSC
will be responsible for arranging for the audio recording equipment to be sent to the
appropriate MEC for the assessment. At the present time, Audio recording of
assessments can only take place at a MEC. Further information can be obtained from
your local MSC."