Conflicting Overseas Wills

My mother recently died in the UK where she has been living for the past 10 years and we have found 2 Wills. One is in the UK and specifically covers UK assets that go to her new husband.
The other is an Australian Will that leaves her Australian assets to me.
My lawyer tells me that the UK Will has been poorly drafterd in that it overrides (revokes) all earlier Wills including the Australian Will which was prepared many years ago.

Is this correct ?? How can a UK Will that only refers to UK assets revoke an Australian Will that only refers to Australian assets ????

if my lawyer is correct, what recourse do I have as I know my mother wanted me to get her Australian assets.