Further as the checking on the Thursday night was markedly different from previous nights it's surprising that he chose that night to strike.
The timing might well have been different.
The frequency might or might not have increased.
However, that changes the probability odds only if an abductor was basing his action purely on timing. If his action was event based, it matters not a jot about the timing/frequency.
The core events were all of the T9 assembled. Starters and mains were ordered.
Window of opportunity for the T9 to conduct another check, as per usual.
Starters arrive. Window of opportunity for abduction, though no bigger than the time to eat a starter.
Starters eaten. Window of opportunity for the T9 to conduct another check, as per usual.
Mains begin to be served. Window of opportunity for abduction, large enough whether an entry point was the patio door, the front door or even the bedroom window.
Mains over. Window of opportunity for the T9 to conduct another check, as per usual.
Not a single person mentions interrupting starters or interrupting mains to do a check. Jane Tanner ate hurriedly, but did not get up in the middle of her main course.
The pattern, to all intents and purposes, was the same as previous nights, thus highly predictable.