The examiner is right that you have to do the initial in an EASA state. Your previous time does count as far as I know. I did the training in NZ, gained the CPL in NZ but had to come back to the UK for the initial IR issue. We were scheduled about 6 flights to get us up to speed with the UK airspace/atc etc. Unless you can get to an EASA state and complete the IR by September I should imagine it is your only option unless you want to redo the ATPLs. For what it's worth, I'd go back as I am not sure I could bring myself to re-doing the ATPLs. As I understand, the UK ones are much more straightforward than the CASA ones so it's up to you (that was just from hearsay as opposed to CASA experience as I have none).