Since the publication of Hoehling's book, most airship historians, including Dr. Douglas Robinson, have dismissed Hoehling's sabotage hypothesis because no solid evidence was ever presented to support it. No pieces of a bomb were ever discovered (and there is no evidence in existing documentation that the sample collected from the wreckage, and determined to be residue from a dry cell battery, was found anywhere near the stern of the airship), and on closer examination, the evidence against Spehl and his girlfriend turned out to be rather weak. Additionally, it is unlikely that Rigger Knorr would not remain at cell 4 to further assess the purported damage claimed by Kubis. In an interview with the TV show "Secrets & Mysteries", Hoehling himself asserted it was only his theory and also suggested a short circuit could be another potential cause of the fire. Additionally, Mooney's book has been criticized as having numerous fictional elements, and it has been suggested that the plot was created for the then-upcoming 1975 film. Although Mooney alleges that three "Luftwaffe" officers were aboard to investigate a potential bomb threat, there is no evidence they were on board to do so, and military observers were present on previous flights to study navigational techniques and weather forecasting practices of the airship crew.