Nice description Gruezi, you are lucky Ned sounds like you did brush it perhaps on the side spikes mate.

I went beach fishing with a mate years ago, everything ready for a good night of fishing. Full esky of coldies, perfect weather and good company. Then my mate walked in the water for his first cast BANG cobbler straight in bottom of his foot

not happy as your body weight forces all the poison available out throught the spike. Straight to hospital, 4 hours later and still in pain I took him home.
Don't think for one minute they only hang out in seaweed, they are in any shallow water especially around dusk onwards. When we where kids we would go with torches and gidgies in knee deep water wearing shoes and spear the bigger ones, bloody good eating.

TIP when walking in shallow water always shuffle your feet and don't take big steps. That way you will get a prick like Ned, still painful but unlikely you will need hospital depending on pain tolerance. Hotwater is the best pain relief, don't quote me but a professional fisherman once told me to put ya foot in petrol as thats better. (
I said don't quote me and someone else may elaberate on that) IMO I'd use hot water.