For the two murders found proven by the court in The Hague, many experts do not exclude a natural cause of death. In the case where digoxin poisoning was alleged, and supposedly detected by independent measurements in two Dutch laboratories, the method used in those laboratories did not exclude that the substance found was actually a related substance naturally produced in the human body. The Strasbourg laboratory used a new method, a test of high specificity and sensitivity, and did not support the digoxin overdose hypothesis. In the second case, the intoxication could have been an overdose caused by a faulty prescription. For both children, it was not clear how and when de Berk was able to administer the poison. Regarding the digoxin case, the prosecution gave a detailed reconstruction of the timing. However, other parts of the evidence discarded by the prosecution showed by the time-stamp on a certain monitor that at the alleged moment of poisoning de Berk was not with the patient at all, and that the specialist and his assistant were with the patient at that time.