This is not as clear cut as the British press would imply.
On Thursday, according to CNN, Italy's Foreign Ministry explained its decision in two parts:
Firstly, Astra Zeneca was ignoring its contract with the EU in order to supply Australia. As Australia isn’t considered “vulnerable” this was deemed sensible.
Secondly, Italy had authorized the company's export to Australia ^modest quantities of samples intended for scientific research activities^ but this export was flagged because it involved over 250,000 doses.
The statement from the Italian Foreign Ministry cited "the high number of vaccine doses subject to the export authorization request” (that being for research purposes) when compared to the amount of doses provided to Italy and, more generally, to all EU countries so far for ordinary use.
This second point - that what Astra Zeneca sent was not in line with the research request, is being overlooked in the media, presumably as it makes a better story without any nuance.
It seems to me that Astra Zeneca is keeping very quiet.