Doubt in lowest time explnation

#1

I didn’t get why node 4 is not having lowest time of its parent node like node 5,6,7 are having?

#2

Actually node has the lowest point to which its children can reach! 4 is visited from 3, so 3 is the parent of 4(hence lowest time for 4 can’t be 3), also none of the child nodes of 4 can reach to nodes 1,2,3.