Not sure what brand primers Hornady uses BUT about 30 years ago I had a FTF in a 270, WW brass, CCI primer. At the time LI lived near Speer/CCI in Lewiston,ID so I took the case to them. They dismantled it sealed it in epoxy and ground away half the case head. They determined the cause of the FTF as a defective primer. What happened was that during the mfg process the anvil starts out as a flat piece of metal that is then folded so that it has three legs connected to the high point. On this primer one of those legs had cracked in the folding process. When the firing pin struck the primer there wasn't three legs to support the crush- the broken leg folded over and the other two collapsed on top of it. The anvil just folded over so the priming compound wasn't crushed. In addition, the primer was pushed farther into the priming pocket so that it looked similar to the picture.
It is possible that happened to the cartridge shown.