Thanks for the edit, I was going blind trying to find the reference to Honduras. That is a good catch.
So, what I think happened is this: Most of these court orders are template orders that set forth the applicable law and basically allow for judges (clerks) to fill in names of parties, countries, etc. Most of the findings of fact are fill in the blank forms also.
In this instance, the Procedural History discusses El Salvador, The testimonial evidence discusses his being a native of El Salvador, and his fear of returning there. I don't have a copy of the filed Withholding of Removal Petition itself, but I am sure it references El Salvador, not Guatemala.
I suspect the "Guatemala" language in the order was simply sloppy draftmanship by the IJ or his clerk, where the last drafted order wasn't edited to change the country to El Salvador. That type of error, a "scrivener's error" is unlikely to prevail legally, especially when the actual "Order" on the last page "Granted" the application, which likely referenced El Salvador.
It is also worth noting that in the Government briefs in latter litigation, the Government has conceded that there was a valid withholding of removal to El Salvador, so no one else has contested the country to which he should not have been removed (much like Garcia himself conceded he was removeable under US law, which removes the relevance of the "deportation" of a "Maryland Dad" argument.)
Edit: Just saw your edited portions of the order. Keep on going down to the "Order" on the last page, it "grants" the application for withholding, which, again, I think was applied as to El Salvador. You did make a good catch on the Guatemala stuff though, most folks wouldn't have caught that (including the clerk/judge who drafted it and the attorneys who received it.)