Peter's Redistribution Pt 2 Post

In the link at the bottom of this post, Peter talks about redistribution.  Basically he wants OSPF to be the transit area for everything, so redistribution happens only between OSPF and the other protocols (i.e. not between eigrp domains and not between rip/eigrp domains).  In the 5th grey config box down (on his post) he shows an output on R1. I've copied it to this post below.  There's two things I don't understand in this post.  

First is why, in the output below, the route to 150.18.5.0 and 150.18.6.0 (router 5 and 6 respectively) only goes via R2? I think it should be going via R3 as well. I find it bizarre that it doesn't as the cost should appear equal from R1's perspective.

Secondly why he states "when we inject EIGRP 356 routes into OSPF, they are not further propagated into EIGRP 123, even though OSPF is redistributed into EIGRP 123." His output on R1 (below) proves this statement wrong as he has both a route to R5 and R6 loopbacks.  The only way I know this statement would actually be the case is if we were trying to redistribute external ospf routes into bgp.  That's not the case here, it's staying between IGP's so external LSA's should be propagated to the EIGRP 123 domain, as proven by his output below.

Rack18R1#show ip route eigrp
     174.18.0.0/24 is subnetted, 3 subnets
D EX    174.18.234.0
           [170/2560002816] via 174.18.123.3, 00:05:52, FastEthernet0/0
           [170/2560002816] via 174.18.123.2, 00:05:52, FastEthernet0/0
D EX    174.18.0.0
           [170/2560002816] via 174.18.123.2, 00:01:36, FastEthernet0/0
     150.18.0.0/24 is subnetted, 6 subnets
D EX    150.18.4.0
           [170/2560002816] via 174.18.123.3, 00:05:52, FastEthernet0/0
           [170/2560002816] via 174.18.123.2, 00:05:52, FastEthernet0/0
D EX    150.18.5.0
           [170/2560002816] via 174.18.123.2, 00:01:36, FastEthernet0/0
D EX    150.18.6.0
           [170/2560002816] via 174.18.123.2, 00:01:36, FastEthernet0/0
D EX    150.18.2.0
           [170/2560002816] via 174.18.123.3, 00:05:52, FastEthernet0/0
           [170/2560002816] via 174.18.123.2, 00:05:52, FastEthernet0/0
D EX    150.18.3.0
           [170/2560002816] via 174.18.123.3, 00:05:52, FastEthernet0/0
           [170/2560002816] via 174.18.123.2, 00:05:52, FastEthernet0/0

http://blog.ine.com/2008/02/19/understanding-redistribution-part-ii/

(link to topology) http://blog.internetworkexpert.com/wp-content/uploads/2008/02/redistribution11.jpg