Polly & Hubby,
When we take on work to a tree with previous damage to it, Or work near say a recently layed retaining wall :eg stumping out stumps we make it quite clear and make them sign off on our quote that we except no responsability to property what so ever, With your tree, and trees that we can see a definate crack/fracture in and we cant get in a cherrypicker and we dont walk which is sometimes the best option, we bind up the section with a good rope it's still scary and you still have to use good judgement but it has worked well for us.
Hope this helps& good luck.
JayD
