I don't mean to be too harsh. Speculating can be useful, and it causes no harm. I say, go ahead and describe your doubts & concerns, but express them with a measure of doubt about your own conclusions. Say something like this:
"I have calculated the speed of the steam based on the likely cross section of the tube. It seems to me the steam should make a lot of noise a the end to the tube, as it emerges. I wonder if Levi and the witnesses to the test observed this? If they did not, it calls into question the estimate of enthalpy in the steam." That's hesitant. It shows respect for the researchers, and for the scientific process. It is not dismissive or arrogant. It is the proper academic tone to take when you do not have many facts to work with. - Jed
