Study: Windows security updates more cost-effective than open source - nothing new, just another Microsoft-funded and therefore pre-determined study with no value. The interesting part about the studies is only the name of the respective company that conducts the study - you can then add that to the corruption list and remember it in case you need to substantiate any statements with falsified and biased studies ...
Otherwise? Well, the standard errors, of course. First of all, no real evidence, but an unspecified list of companies that were asked what they think about it (as opposed to collecting hard facts). And of course, equating Red Hat with Linux - which is sheer nonsense in itself.
From personal experience with both systems, I can say that our Debian GNU/Linux systems are much easier to keep up to date and therefore much cheaper to patch than the Windows boxes. And this despite the fact that both use their integrated update mechanisms over the network (and for our Windows systems, even fueling stations and internal update servers exist). But I wouldn't be asked for such a study - I wouldn't fit into the Microsoft-funded picture ...