Out of all the approximate mess of a timeline in the case, Mr McCann gave an exact, most precise time. No one else really could but him. He must have looked at his watch, then, tried to claim that Kate was searching the apartment for 10 minutes. It doesn't make sense, & if it doesn't make sense then it most likely isn't true.
I saw this extract from Kate's book today
Refusing to acknowledge what I already knew, and perhaps automatically going into a well-practised medical-emergency mode I checked the wardrobe in the children?s room. I ran into the kitchen, throwing open all the cupboard doors, into our bedroom, searching the wardrobes, in and out of the bathroom, all within about 15 seconds, before hurtling out through the patio doors and down towards Gerry and our friends.
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Mr McCann was apparently worried by Kate's unusually long check. About 10 mins he claimed, when
she claims it was only very brief, a quick scour of the apartment. The alarm was raised prior to 10pm according to Russell & Matt's evidence. Then, after the alarm was raised Mr McCann, according to Russell, Mr McCann was the first to suggest they split up & search.