The woman asked the flight attendant to ask the man to remove his Knee Defenders. That is completely civilized behavior. The flight attendant asked him to remove the Knee Defenders. She had more than a leg to stand on, because those are prohibited to use on the airline. The man refused. NOW we're entering uncivilized territory. He was politely asked to remove those things so that the woman could get what she paid for, and he decided to be a harda@@ and refuse. I don't know if I would have thrown water on him, but more than likely he said something nasty and stupid to her and she just reacted, after being frustrated by his VERY unchivalrous behavior.
Much more likely HE is a Demojerk. The woman paid good money for the flight. She is entitled to be comfortable. For me, going to Denver is a long flight of several hours. I will be darned if I am going to be forced to spend all that time in an upright position so that the guy behind me can be comfy. A compromise has to be reached. I recline my seat a little, not all the way back, and he can do the same.
Indeed he sounded like an ass, but “heated” and “diverting” and “both thrown off” sounds a bit more than just tossing water.
Bottom line, instead of ASSuming she can just back into someone, she should be the first to ask if it is OK to recline. [You said she paid money and is entitled to be comfortable (hah, on airlines these days?) - so why not him?]
Sorry, but it is true that they recline more than is really "comfortable" for the next person. I guess that is if you are on a half-empty flight and it doesn't matter.
I already went over the etiquette rules in my first reply.