Hello Scipio thanks for that I was always under the impression that Julie's evidence alone was not enough to convict him but on reflection I guess at the end of the day it was all down to who the Jury believed Julie or Jeremy and I guess they believed her. One would have thought the Defence would have tried to discredit her in someway i.e. cheque fraud drugs but maybe they are not allowed to do this in Court.
Right in a he said/she said situation the trier of fact (jury in a jury trial/ judge in a bench trial) decides who to believe. If there is evidence that establishes either is lying that makes it easier to tell who to believe.
The defense could potentially have wanted to question her to try to establish she lied as a back-up plan so that even if they fail in discrediting the moderator that they could try to get a retrial by virtue of undermining her evidence.
The defense could also have wanted to question her to see what she remembers if anything simply as a preview of what her testimony would be in the event they did manage to get a retrial. If the moderator evidence were tossed her testimony would be even more significant in a retrial. If they found out that she would make a useless witness that could end up resulting in the government not even bothering with a retrial. It also could help them find some weaknesses based on her memory failings. So they could have essentially wanted to do strategic probing which can be considered underhanded but lawyers do such things fairly often. I can't even begin to tell all the different games that are played.