Me thinks that there has been a lot of rot talked about the dry version,
Seriously if the original timber had been treated against this fungus then it would not grow! Usually these timber treatments involve a copper compound which stops the fungus.
Dry rot only 'grows' in specific conditions. A certain level of humidity and a lack of air movement.
If my memory serves me well -and I not sure it does! On very windy days you get air movement along Smallcleugh horse level, so in theory at least timber on the floor will probably be Ok, but down the hole it would be better to have it treated first.
I would put my underground suit for washing immediately when I returned home because the spores can travel- but must have the correct conditions mentioned earlier to infect new wood.
Good for you Nick,