That's not what the article says. It says 1) they didn't confiscate the phone after the incident, and 2) there were no pictures when they later checked.
He was not detained because there were no pictures on the phone. Luckily there is no feature in a phone that lets you remove videos or photos once taken, otherwise his innocence beyond reasonable doubt might be questioned.
Deleting a photo off your phone does not wipe the data, they can recover that in seconds after plugging your phone in and copying all the data which is frequently done at airports.
I would agree with you except it says the father was shown no pictures and later that the FBI didn't arrest him. What it doesn't say is the duration in between dad and FBI. There is not some permanent record of deleted files in your iPhone if you keep using it and it's not confiscated. It doesn't read like authorities picked the FA up at the stop, but more like this is a protracted dispute.
Even if no pictures in the first place it's still suspicious AF and the sort of thing I would expect to receive a special visit by Chris Hansen.
Photographic evidence of said phone in a compromising position.
This is all evidence. There's no refutation in the article. The only thing that is not there is some direct indicator of intent. It was enough to warrant a phone search and to dismiss him from work, and a clean search doesn't mean dick by itself because intent to snag this kind of photo is also a punishable offence:
Do you expect the journalist ever got a chance to speak to the attendant?
When they rang the company to speak to them about the incident what is more likely “Oh yeah sure I’ll transfer you over to him have a nice chat” or “We here at Flight Company take all matters very seriously and will look into the matter”?
Why do you assume because this article is one sided hearsay, that it must be the truth and journalists investigated every angle so a lack of mention is an omission of guilt?
I expect that people are basically good and that nobody is out to frame this person. The fact that they are not named makes it much easier to discuss the situation on the merits and is the only reason I'm commenting. It's not like this is some rag news site and anything that the girl or the FA write is necessarily hearsay since airlines don't have bathroom cams. There is no reasonable "other side" I can conceive which would also play the role of reasonable doubt.
More to the point, the case doesn't have to be solved beyond a reasonable doubt to investigate in the first place, or to report on. If AP News named him I would also take issue, but that isn't the case right now.