The shooting at the Austin hotel seems to have nothing to do with open carry, other than the person doing the shooting was carrying the gun openly when he committed the crime.
He is just doing agitprop, there are so few examples of people openly carrying before committing crimes, that he has to make stuff up. Openly carrying a gun while committing murder or robbery is already illegal...
http://www.nydailynews.com/news/crime/gunman-killed-police-swanky-texas-hotel-cops-article-1.2282374
The shooting in Austin occurred before 5 a.m. in the hotel lobby.
The recent Open Carry Movement in Texas has been related to handguns.
Long guns in Texas have been legal for open carry for years and years, even if select law enforcement officials don’t know it or disagree with it. No permit has ever been required.
The hotel incident has nothing to do with the recent authorization of open carry of handguns by permit holders.