A couple of points which I must highlight. Eddie's alerts in the apartment and the hire car could have been to many substances other than that related to a cadaver. Martin Grime admitted this.
Do not therefore assume that if Madeleine died in the apartment she had to have lain there for at least 1½ hours. Madeleine's death in the apartment, if it happened, does not necessarily have to be in any way associated with the later dog alerts.
Please always think outside the box.
What many substances are these? The dogs alert to two things and two things only. Eddie was trained to alert to blood and cadaver scent and Keela to blood. Can you cite where Martin says they alert to anything else other than these? They were deconditioned to alerting to urine, semen and faeces unless they were mixed with blood so you can rule those out. Where Eddie alerted alone and Keela did not, he was alerting to cadaver scent only.
In Martins opinion where Eddie alerted alone he said and I quote
'My professional opinion as regards to the EVRD's alert indications is that it is
suggestive that this is 'cadaver scent' contaminant'
http://www.mccannpjfiles.co.uk/PJ/MARTIN_GRIMES.htmAlso, I do not assume that a body would have to have lain for 1.5 hours before a dog would alert, I base what I post on hard facts.
A body would have to be insitu for at least 1.5 hours as it would not be possible for a dog to alert to cadaver scent earlier than that as the general consensous among scientists is that chemicals from decomposition only appear once a body has began to decompose. It takes our organs up to 90 minutes to die. Decomposition won't start until after the last organ dies so a body would have to have been insitu for over 90 minutes for any scent to develop and be detectable by a dog like Eddie.