Galvao didn't bring a lot to the fight it seems and was very one-dimensional, relying on a shoot to tackle his opponent and take the fight to the ground where he hoped to employ his far superior Jiu Jitsu skills to win a victory. However, it was Galvao's futile attempts to shoot that got him into trouble. The fight effectively ended at around the 2:40 mark when Galvao shoots, fails and is seriously hurt in the process of launching his own - for the most part, undefended - attack
The thing is that almost twenty years ago, when what is now known as the Ultimate Fighting Championship first started, Galvao would have most likely come away as the world champion. Afterall, he isn't trying to do anything that Royce Gracie wasn't doing successfully back in 1993 to dominate fighters who were for the most part much bigger, heavier and stronger than he was. Royce won the first Ultimate Fighting Championship against Gerard Gordeau by following the same pattern that Galvao attempted against Tyron Woodley. Gordeau didn't know what was coming and didn't know how to defend himself; Woodley knew what was coming and was easily able to defend himself.
Both Royce and Galvao are using the same game plan to enable them to use their Brazilian Jiu Jitsu skills: shoot in low, take the fight to the ground and secure the win. Royce was able to shoot, take Gordeau to the ground and win without suffering any damage. Gordeau was clearly out of his depth and simply didn't know enough to be able to even attempt to counter Royce.
Seventeen years later and the same game plan using the same style results in a comfortable win for Tyron Woodley.
The difference is that while Royce was incredibly successful, Galvao ended up getting beaten precisely because he was putting himself in such a vulnerable, exposed position as he went for the shoot against a fighter who knows how the BJJ crowd do things and has trained to counter such take down attempts.
Twenty odd years is a long time. Almost a full generation. And in that time the opponents of Brazilian Jiu Jitsu practitioners have become wise as to how to counter the shoots to their legs (by 'sprawling') and what was once a match winning tactic has now lost it's value of surprise and has become a simple technique / strategy to counter.
As the difference in results in the matches fought by Royce and Galvao prove, Brazilian Jiu Jitsu by itself is inadequate to gain victory.
The issue is far more complex than that though in my opinion and I think a fighter nowadays needs to evaluate just how useful time spent learning Brazilian Jiu Jitsu actually is.
First of all I want to say that I am not dissing BJJ. I find it challenging and fascinating as an art in its own right (I train in BJJ, both Gi and Non Gi) and I don't think the art stands or falls according to whether or not it is useful to today's Mixed Martial Artist. What I do feel though is that the reputation it has built for itself as being relevant to MMA has been due more to the lack of awareness opponent's of the style have had in the past than the overall effectiveness of BJJ.
Around the time Galvao was losing to Woodley we also saw BJ Penn lose twice to Frank Edgar. Penn is a well-known BJJ expert and, like Galvao, another former world champion. Edgar is a purple belt in BJJ and there is no indication that he is anything more than an average purple belt at that. Yet in both fights it was clear that Edgar didn't need to be anything more than a purple belt. He didn't really use his own BJJ skills in either fight; rather he just needed to know enough to make sure he could avoid fighting on Penn's terms. Seen from Penn's point of view, it is clear that BJJ by itself wasn't enough to win either fight.
At UFC 119 Matt Serra, a contemporary of BJ Penn on the BJJ circuit and another world class practitioner, didn't even really try to use Jiu Jitsu and instead just banged with Chris Lytle. He may have had an ulterior motive here: to take the 'Fight of the Night' award that he talked about in interviews. But he lost the fight, never looked convincing and was out of gas for much of the second half of the fight.
So in response to the question: Are we seeing the death of Brazilian Jiu Jitsu? I would have to say that yes, we are. BJJ remains relevant as a martial art to study more because of a few standard, but very effective techniques it employs and because, for as long as other people are doing it, you need to know enough to counter what they have. But with world champions in MMA nowadays having limited experience or ability with BJJ just how long BJJ remains relevant to the MMA fighter is highly questionable.