Causes of downfall of a Man, pointed by Buddha in Mangala Sutta As, pointed out by Buddha in Mangala Sutta, the causes of downfall of a man. Among those following is the one among them;
1) Those who have ample wealth does not support his old aged father and mother has a downfall!

Question remains, How if pursuing the goal of Nibbana, one abandoned the all relation and property. Including that of old age mother and father, won't have Downfall.
How, if that 1st statement is assumed valid, there was not a downfall of Buddha, although abondened his old age parents?
Please answer the above correctly!
Among those following is the one among them; 1) Those who have ample wealth does not support his old aged father and mother has a downfall!


Philosophy aside, just by going with plain simple logic and there's no contradiction here. The statement and the premise is clear: those who have ample wealth who do not support their aging parents will face downfall. The Buddha and His noble disciples did not have ample wealth and hence did not satisfy the condition for the downfall. Now including the philosophy, one can safely say that what the Buddha did at the end for His parents, siblings, son, their many relatives, and countless many people was an extraordinary kind of support no other worldly support was able to match:


  "I tell you, monks, there are two people who are not easy to repay. Which two? Your mother &amp; father. Even if you were to carry your mother on one shoulder &amp; your father on the other shoulder for 100 years, and were to look after them by anointing, massaging, bathing, &amp; rubbing their limbs, and they were to defecate &amp; urinate right there [on your shoulders], you would not in that way pay or repay your parents. If you were to establish your mother &amp; father in absolute sovereignty over this great earth, abounding in the seven treasures, you would not in that way pay or repay your parents. Why is that? Mother &amp; father do much for their children. They care for them, they nourish them, they introduce them to this world. But anyone who rouses his unbelieving mother &amp; father, settles &amp; establishes them in conviction; rouses his unvirtuous mother &amp; father, settles &amp; establishes them in virtue; rouses his stingy mother &amp; father, settles &amp; establishes them in generosity; rouses his foolish mother &amp; father, settles &amp; establishes them in discernment: To this extent one pays &amp; repays one’s mother &amp; father.” ~~ AN 2.32 ~~