http://www.rigpawiki.org/index.php?tit ... iginationThe twelve links can be explained as a process occurring over three lifetimes:
(i) The past cause of ignorance and karmic formations lead to the result of (ii) one’s consciousness of the present life and the links up until becoming, through which one accumulates the karma through the negative emotions of craving and attachment, that will lead to (iii) a future rebirth. One takes birth according to one’s karma and experiences the sufferings of old age and death and so one.
Or over two lifetimes:
(i) The ignorance of one’s previous incarnation, and the karma created through the power of craving and attachment, cause (ii) one to take another birth, and in that present life there arise the links from consciousness through to becoming and old age and death.
There is (liberation palm your hand page 126) a story where brahmin and ksatria are talking what they want to do with Sangha.
Brahmin wants to kill them and ksatria wants to feed them. They take a nap. Brahmin lose his head by a runaway cart. Ksatria sleeps under the tree and trees shadow doesn't move and he's rewarded by position of leading merchant.
Why their karma caught them in same lifetime they did that action?
It should happen in their next lifetime. Why it did happen in same lifetime?