But really, if he bowled at 180 kph the difference between that and even express bowlers like Lee, Akthar, Tait and the genuinely quick ones like the Lillee's (early days), Marshall, Holding (though he was probably express as well) would surely be discernable from the footage.
What I mean is, Thommo looks really quick in the footage, but so do the other fellows I've mentioned. If he was THAT much quicker than everyone else, wouldn't you notice it?
Likewise, Marsh stood a long way back to Thommo, but if you see the old footage, is he that much further back than other keepers to other really quick bowlers? I know that's hard to tell from camera angles and all, but it seems to me unlikely he or anyone else ever reached that speed.