You're right, that information is a little confusing. I am inclined to believe the news article's version of events. She needed a ride to the bowling alley from her father's residence, I'm assuming. This tells you that she was home alone... her father/brother weren't home to give her a lift to the bowling alley.
What happened when the boyfriend got to the house? Was he aware that she was tired of waiting and just started walking to the bowling alley - did he try to head back to the main road/the direction of the bowling alley to pick her up along the way? Wouldn't he have seen her walking, if he only got there five minutes after she set out on foot? If he didn't get an answer upon ringing the doorbell, would he have just shrugged and been like "I guess she didn't want to go out tonight after all?" and went back home? Who told him that she had left a mere few minutes after he arrived at her home?
Can we even believe the boyfriend's credibility? Sorry but as you can see, I have a LOT of questions regarding the events of that evening.
All of these are very good points. What is the source of the claim that Katheryn left on foot when the boyfriend was late? Obviously not the bf, since he missed her by 5 minutes. And maybe not the dad or brother since, as you say, if she needed a ride, that suggests they weren't home.
Or... the only thing I can think of is that the dad and the brother
were home, but maybe the dad needed his car (assuming he had a working one) for other plans that day, and thus wasn't available to drive Katheryn to the bowling alley. This would explain why the bf would've had to pick her up, and why someone would know he missed her by 5 minutes.
And it would also explain the reason given behind her walking. A random motorist would've just reported seeing a girl walking, but would have no way of knowing
why she was walking.
But then again, from the map
@SAMS provided, it's about a 2-hour walk from the residence to the bowling alley. Would the dad really have been comfortable just letting her go out and walk 8 miles? Especially when her ride is not even 5 minutes late by that point? Was Katheryn really that headstrong—like, "oh, he's 2 minutes late! I'm just gonna walk!"
The boyfriend situation isn't clear, and neither is the "visiting Dad" situation. It was July, so maybe she and the brother were spending the summer there? Or possibly a few weeks? She was only 17, the "boyfriend" could have been a boy she met there a few days prior and they quickly decided to be boyfriend/girlfriend, you know how it is at that age lol. And yes, I would like to know who last saw her/when/where, and also if anyone actually saw her walking.
As for the boyfriend situation...
Katheryn was said to be from Georgia. I don't know how it was back in 1981, but
from what I've found online, the school year in Atlanta ends in May, shortly before Memorial Day weekend. Assuming she and her brother had left that weekend (or shortly thereafter) to spend the summer with their dad, she would've been in Delmar for a month and a half. Plenty of time to meet someone and have a summer fling/relationship etc.