Yes I agree that fight had a great deal of interest but the nfl is their real goal.

Some ISPs have on-site Netflix Open Connect racks. The advantage of this is that they get a high-priority quality of service data stream into the rack, which then serves the cached content to the ISP customers. If your ISP doesn't have a big enough Netflix rack and it gets saturated, then you're getting your streams at the whim of congestion on the open internet. A live stream is a few seconds of video downloaded, and it has to make it over the congestion of the internet in a few seconds and then repeat. If a single one of these repeats hits congestion and gets delayed, you see the buffering spinning wheel. Other shows, on the other hand, can show the cached Netflix splash animation for 10 seconds while they request 20 minutes of cache until they get it. So, dropped packets don't matter much. Even if the internet is seeing congestion every couple of minutes, delaying your packets, it won't matter as non-live content is very flexible and patient about when it receives the next 20-minute chunk. I'm not an ISP or Netflix engineer, so don't take these as exact numbers. I'm just explaining how the "bandwidth problems might be localized" hypothesis can make sense from my general understanding.

Even if it was only 30% of people had a problem that's still millions of unhappy users. Not great for a time sensitive event.

Also, from lurking in various threads on the topic Netflix's in app messages added to people's irritation by suggesting that they check their WiFi/internet was working. Presumably that's the default error message but perhaps that could have been adjusted in advance somehow.