An answer from an Arizonan:
Bobcats are really good climbers. Normally they only climb mountains and large rock formations, but perhaps this one was threatened, and had to flee, and the cactus looked easy to climb. It most likely didn't get hurt doing so, saguaro cacti have long, straight thorns, so their easy to avoid, and easy to remove. Eventually, the cat will either climb down, or fall, or some rangers will come rescue it.
Comments
Bobcats are really good climbers. Normally they only climb mountains and large rock formations, but perhaps this one was threatened, and had to flee, and the cactus looked easy to climb. It most likely didn't get hurt doing so, saguaro cacti have long, straight thorns, so their easy to avoid, and easy to remove. Eventually, the cat will either climb down, or fall, or some rangers will come rescue it.