More reading about the PP experiment shows that it just measures the electric conductivity between two points,leo vuyk wrote: Water ice under Philae!
The PP experiment used a number of electrodes to transmit alternating current through the comet surface and was able to detect that there is a large quantity of water ice under Philae.
using alternating current. Not what the actual material is. There are many alternatives.
The experiment, if done correctly, may exclude some materials, even water.
Did they find a release of H² and O² in the material at certain voltages? And how much?
That would be interesting. There may be a little water, due to the solor wind.
Did the electric waves show echos in the material? Is that what they measured?
It may indicate a solid structure underneath the dust, which could be anything, but is not ice.
The whole body is clearly too light for ice (ice=0.9 g/cm³).
Which means that, if they found a solid body, that there is no ice.