Wow that's pretty amazing that that goof made it past all the QC checks from the factory. I mean doesn't someone double check when the first revision is drawn up on the instructions?
Not once, but at least twice.
I found the Italeri instructions online, and they're a direct copy--- at least that part of it. I guess if you've never seen WW1 a/c, it all looks the same. [I confess, if it were, say, some part on a historical locomotive...I probably wouldn't be able to tell the difference. Just not my area.]