He was misreported as working for a steel company. It's technically true, of course...just not very descriptive or useful.
The presence of an ex-RAF cyclist, the one who reported the shooting, could just be coincidence...but it has to be said, that's an awful lot of military links to a murder. Ex-military are frequently used in intelligence, if we're taking the assassination angle on this, could he have been shadowing one of the two murdered parties? Something to consider, especially if we consider the "meetup" hypothesis above.
I know the French think there might be some inconsistencies in his story, they want him to redo his bike journey.
However, if this was an assassination...well, lone assassins are either criminals or lunatics. You use teams to carry out assassinations, everyone with the manpower to do so knows that. But French ballistics say all the shots came from one gun.
Some are suggesting that Haydar Thaher, son of one of the victims, might be responsible. He has mental health problems, has made violent threats against his family before, and has been missing for a month. His mental illness seems to be schizophrenia...but I don't know. The scene was described as a massacre but this looks like the kind of killing done by someone who has done it before. I considered a serial killer when I first heard the news, but it's very hard to leap to this kind of cold-blooded killing without previous experience...and from the sound of it, the local area tends to be very quiet, peaceful and has little in the way of violent crime. Of course, I'm not privy to all the criminal reports in the region, and the possibility of someone coming into the region from somewhere else cannot be ruled out, but at the same time, I would hope for more indicators than "mental illness, reports of violence" for such a ruthless killing.