It could well be.
The website I found it on said it was a Harley. But as they were more focussed on the cage, they might have assumed it was a Harley, not knowing of the existence of other US makes like Excelsior, Indian, etc. Much as people brand all medium sized vans as "Transits" and all small 4x4s as "Jeeps".
I suggest we leave things as they are unless (until?) someone comes up with a definitive answer.