Many manufacturers only stitch weld those rails.
It could've been welded by a newer, yet still experienced welder here, but, to his defense, the Hardox AR450 material, which is far superior in strength and abrasion resistance to anything else used in the industry, does require more starting and stopping, to prevent bowing, rather than keeping it full blast all the way across.
Also, if you'll notice, that the bead gets fatter, and then thins out at the notches, to avoid interference with the tine locking(which would really throw down and oh

flag).
I have never ever ever seen a failed weld on EA pallet forks. Ever, and I doubt we ever will.
I have, however, seen some other brands fail, due to poor and/or stitch welding..
I hope this helps to explain.
Travis