This sounds like a reasonable solution unless there is concern for compromising the strength or function of the fitting.
I like sending it back-- though it's time-consuming, if you've got the plans or written specs and can show they did err on it, leave it up to them to repair/replace and don't sweat the responsibility for what's not your fault.
(Please, just, whatever you do, don't go to 'handy-crimp' lifeline fittings. They're all about the customer's own swaging process; and unless you're really, really experienced in this, it's way too easy to make a small mistake and have a fitting that'll hold nothing. Worst of all, it's hard to tell when you get it wrong till you apply a shock load-- like, oh, let's see, a guy falling into the lifeline or reaching for it and landing with a bit of a bump. Then, of course, it's too late.)