I've been flying in and out if Moorabbin for nearly 7 years and am yet to see an aircraft in the circuit that is obviously too low. Of all the flying I have probably been lower than anyone elsen I have seen, it happened on a special VFR clearance when the cloud turned out to be a lot lower than everyone expected, around 400ft however I conducted a straight in at reduced power for that return to the field to keep the PaulDamiens of the world happy.
So 43 inches, did you give chase to a crim with a gun over Cheltenham? Sounds interesting. I've had a couple of chases in my time, a crazy gunman with high powered weapon and a firebug attempting to get away, all good fun except the gunman shot himself. See, airports are a safe place!