In the first post Redis + asynchronous replication + (an alpha version of) Sentinel were found to lose writes during partitions. This is an obvious result of asynchronous replication + failover, since this is, technically, an eventually consistent system where the merge function is picking a single timeline when there are divergences. Redis was improved since then by adding heuristics to practically lose less writes, but basically this was an expected result that nobody can change.
In the second blog post I proposed, just for an argument of a different discussion, a strongly consistent system where basically you have God coordinating the failover, and every write replicated N times. This is something that's not even worth to test, since it is obvious that a system like that is linearizable, however it was still tested, and since it was obviously flawless per definition, the flaw was found, very surprising, in something that violates any CP system, that is, serving reads directly without any agreement. Later Aphyr in this article (http://aphyr.com/posts/316-call-me-maybe-etcd-and-consul) pointed to reading from a possible stale leader as a flaw, while in its implementation in the previous article he setup the things in order to explicitly read from nodes directly.
In both the instances I can't see how this translates to me not understanding stuff. That said, distributed systems are all about details, and while I'll try hard to do my best, I can still end with something buggy. I try to improve my knowledge every day and I understand I'm not an expert in the field and that I need to learn, test my designs, make them publish in the hope that other people will analyze them, and so forth. However I believe I'm not the only one that needs to perform this learning process, especially if you want to point at random articles on the web as evidence of my failure, you also need to have a solid understanding of the basic principles.
Totally off-topic, but I have such a fangirl crush on Salvatore Sanfilippo... Every time he posts I get butterflies.