Ok - overall, it went well. The feedback I got from the person supervising me was mostly positive, it was never (and never will be) going to be perfect, everyone always learns. The claimant was very patient with me and overall was very accomodating during the interview.
Had one mini stuff up which I won't go into here (we all stuff things up though at some stage though and thats how we learn) , but it just means I have to see the claimant again tomorrow to get him to sign the statement and review it. Basically, up until the mini stuff up I was doing really well but then got flustered and wanted the earth to swallow me up right there and then, but it wasn't until after the interview was completed that the supervisor said to me that it wasn't a major stuff up and its fixable and that I was doing fantastic up until that point. All good though.
Overall for my first one I was happy and relieved it went off mostly without a hitch. Still have lots to learn but that is to be expected. The feedback I got at the de-brief afterwards was positive and constructive at the same time.