Welll, I would say it's not typically normal. Since it isn't obvious who the pasture belongs to it's possibly he didn't know about it til it was to late. I am in Arkansas to, never lived anywhere else, so I won't pretend to know how they do things anywhere else. I know a guy that owns property all over town, and keeps cattle on several different places (or did at one time) and most likely rarely saw his cattle, they generally only got messed w/ when he'd gather up the calves to take them to the sale. Generally they did alright, and I think if there was a problem he knew about he'd do something.
How much a person does generally depends on what they breed cattle for, show people are generally going to put in more. My parents have both own cattle (and when I say we I'm going to be refering to my parents cattle, because I'm generally their go to helper), they've generally ran purebred bulls w/ mixed cows, bull calves and any non keeper heifers are taken to the sale barn, the bull is w/ the cows all year bulls don't last long because we keep heifers back and don't want him breeding his daughters, for most generally a cow lasts as long as she's productive, most are sold because they came up open, not because they broke down. In our case the oldest cow (beef cows) we have is in her teens and just had a beautiful little bull calf! She missed a year or two, but has done her job for atleast the last two years. She's showing her age, but I'd imagine anyone would after popping out a calf every year since they were 3. I also own a beef bred steer that's in his teens, and very fat and healthy! In our case I'm the go to girl w/ any problems, and I get to take care of them. We have had two cows down that I can remember, both were calving injuries, one wasn't down long, the other if I remember right was down about 2 weeks. If she'd be were people could see her they may have assumed she wasn't being cared for, we'd take her feed and hay, the feed was cleaned up pretty quickly, and the hay wouldn't last long either, we also flipped the cow over a couple times aday, but most care was given after dark. She didn't die and eventually got up, but ended up w/ a perminate limp.
Different people have different opinions about how much they will do or spend on a cow/calf. Most I know will care for a down cow, and if they won't are willing to shoot it atleast. Many don't want to deal w/ bottle calves, either because it's not worth the money they put into it, or they just don't want to be inconvenienced, so they will be taken to a sale or given away. I don't know what my parents would do w/out me, but right now they just give them to me.
So I'd say, no the situation is not typical, BUT getting someone to help when you get involved is generally not that easy either, I know I couldn't get anything done if I had the same situation (and it was neglect, not the owner just not knowing).