Why difference in karmic effect to same evil deed?

According to the [Lonaphala Sutta](http://www.accesstoinsight.org/tipitaka/an/an03/an03.099.than.html) , a minor evil deed done by a spiritual novice would take him to hell, while the same minor evil deed done by the spiritually advanced would be barely experienced. In the sutta, the Buddha gives more analogies like the salt crystal in a cup of water vs the river, the poor thief vs. the rich thief etc. which definitely work as analogies. But then could anyone explain why is it really like that? How to make sense of it? > "There is the case where a trifling evil deed done by a certain > individual takes him to hell. There is the case where the very same > sort of trifling deed done by another individual is experienced in the > here & now, and for the most part barely appears for a moment. > > "Now, a trifling evil deed done by what sort of individual takes him > to hell? There is the case where a certain individual is undeveloped > in [contemplating] the body, undeveloped in virtue, undeveloped in > mind, undeveloped in discernment: restricted, small-hearted, dwelling > with suffering. A trifling evil deed done by this sort of individual > takes him to hell. > > "Now, a trifling evil deed done by what sort of individual is > experienced in the here & now, and for the most part barely appears > for a moment? There is the case where a certain individual is > developed in [contemplating] the body, developed in virtue, developed > in mind, developed in discernment: unrestricted, large-hearted, > dwelling with the immeasurable. A trifling evil deed done by this sort > of individual is experienced in the here & now, and for the most part > barely appears for a moment.