Harry Price: What perplexes you, Mark? Mark Kerr-Pearse: I'm really not too sure to be honest. I'm just grappling with my own recollection of events. Harry Price: Well that's always the difficulty isn't it? It's why using a witness could be a difficult away to corrupt a raised event. Mark Kerr-Pearse: How so? Harry Price: Say you meet a friend at a train station. You haven't seen each other in some time. You drink together. You drink together, you talk, you laugh. You part company and then you decide to tell the next person you see what happened. Well you recount the event perfectly word-for-word, conversation-for-conversation but still, small details slip, mistakes are made. You were asked; "what did your friend wear?" and you think "was it a red tie or was it a blue tie?" Mark Kerr-Pearse: Memory. Harry Price: Memory. It's why note taking, photographic proof. These are all vital to piece together exactly what happened. Mark Kerr-Pearse: Because memory can be fallible Harry Price: Exactly. At least that's what I recall.