If the Seafire could obtain a very favourable 10:1 kill ratio over the Zero, Australian Air Force Spitfire claims are probably quite reliable, and may not be inflated at all.
The 10:1 you cite is a claim. I don't see how one claim can measure or validate the accuracy of another claim.
Seafire v Zero was covered earlier in this thread (or anyway several times counting all related threads

). There was only one combat between the two types that be documented from two sides. That was morning of August 15 1945: Seafires in rare use as escorts on offensive mission were credited w/ 7 Zeroes for 1 loss. But known Japanese accounts gives losses to Seafires that morning as: Lt. T Honma of the 252nd Air Group bailed out WIA, and CPO S. Yamada of 302nd Air Group WIA but apparently landed safely. A number of other losses were attributed to F6F's (which also made a lot of claims similar time and place, overlapping combats). Source is Maru Special, "Pacific War Sea-Air War Series". Honma's detailed account is given in "Sky of August 15" by Hata.
However the real comparison to make in trying to figure out real results is the relative clarity of the situation and completeness of opposing accounts. In August 15 '45 case there's some room for doubt about completeness, and room for confusion about losses due to Seafires or F6F's, though the full claims of the Seafires are hardly likely (nor the full F6F claims, nor any typical WWII claims).
In Darwin 1943 in contrast, detailed published Japanese losses mostly link back to a privately published monograph by a retired JMSDF officer, commissioned by a Western researcher. He compiled and translated the handwritten action reports of the 202nd Air Group over Darwin.
-those reports survived complete and intact for each Darwin mission
-the 202nd was the only Zero unit over Darwin per multiple Japanese sources (in the single raid by Army a/c, a 59th Fighter Regiment 'Oscar' was also downed)
-there were no other Allied units making claims at the same time
-they had a 500 mile return trip: fewer questions about damaged v lost than in actions right over their own a/f's as in 1945
There's little reasonable doubt about the Zero losses over Darwin or the high overclaim ratio by the Spits. Again the best recent published source IMO is Baeza "Soleil Levant sur L'Australie".
Besides Aug 15 '45, Seafires claimed a few other Japanese fighter types without loss (I think the claimed ratio was actually a little higher than 10:1, August 15 was IIRC their only air combat loss), but it's not clear if any of those other a/c were acting as fighters, rather than kamikazes: the Seafires were on defensive CAP missions. For comparison, the FM-2, which was mostly also used for carrier (CVE) defense in late war claimed 18[3] fighter type a/c for 7 air combat losses, 26:1, Sept '44-Aug '45 (Naval Aviation Combat Statistics). So even if we had enough of a sample to say much about Seafire v Zero (we don't) we'd have to put it in the context of the particular mission (with kamikaze/fighter confusion in some cases) and of 1945 Pac War air combat overall, very different, in many more ways than just tactics, from air combat v a still pretty first string Zero unit like the 202nd AG in 1943.
Joe