I think that there was a lot more emphasis on ASW in the competition than the RAN gave out, becuase that is besically THE part where the T26 really shone compared to the other designs. Otherwise it would have made more sense to go with the Hobart derived design.
From what I gathered the RAN made it clear from the get go, way back in 2009, that the Future Frigates were going to be heavily geared towards ASW, which made the Type 26 the favourite to win leading up to the decision. Navantia's offering only ever really seemed to make sense from a cost and time point of view, which are of course very important, but even then maybe memories of the initial bungling of the AWD construction was fresh in the minds of those making the choice. That's not to say it would have been a bad design, just not as good.
FREMM always seemed an outside bet for SEA5000, wedged in between the high-end option (T26) and budget option (F100), and Fincantieri is basically non-existent in Australia anyway, it would have required going through the whole Navantia process all over again but with a different company. Doesn't help that the FREMM design doesn't have a huge deal of growth margin, from what I hear, and would probably require far more integration work than the other two designs, even just going off armaments, let alone combat systems and the like. Again not a bad design, and certainly better than F100, but in this case it seems that the RAN wanted the best capability possible, whilst Government wanted a reasonably fuss-free industry plan that could also open up potential defence export opportunities (Bushmasters are already being offered for the UK's MRV-P program). IMO, it was always going to be between BAe and Navantia