I agree with you there LASTMINUTE, unless WAH has access to information not provided by the AAIB then the chip and not HUMS seems to be the starting point. They make no mention of a HUMS exceedence prior to the last flight. It also seems likely that the close monitoring 25 hours had also been concluded prior to the last flight. Normally a specified period is put in place for close monitoring and 25 hours would not be unusual.AAIB "HUMS data was downloaded and analysed each time the helicopter returned to it's base at Aberdeen for the next 25 flying hours. No further abnormalities were identified DURING this period."Just my interpretation of the AAIB statement