Boolean Difference fail yet intersect is good it seems?

[Steve1]

Hi,
V5
Boolean Difference fails, grey object into brown. , I check intersect and all appears good, have I missed something ?
both are closed polys details tells me.
made with Pipe command 0.01 to 0.001 then boolen union the result.

Boolean Difference fails.3dm (529.1 KB)

Cheers

Steve

[Gijs (Gijs de Zwart)]

your tolerance is 0.001, which is too rough for this kind of detail:
If you change to 0.0001, the Boolean and Intersection will be better