It is possible. I have not seen many fake pasteup pairs until recently. No 4-cent horizontal imperf coils were produced, so comparing the edges and perfs with a graphic overlay could be definitive. Even so, comparisons can produce an expertizer angst. We have multiple possibilities starting with genuine. That would be good news. We have good news, bad news possibilities. The coil is good but the pasteup is not. Bad news possibilities include trimmed sheet stamp pieces pasted together or imperf pieces cut to resemble a coil with fake perforations added or mixed, one from column A and one from column B pasted together. Which is it?
Three possibilities: Genuine, genuine coil with a fake pasteup piece with fake perfs added or a trimmed sheet stamp with a pasteup piece with fake perfs added. The latter possibility seems unlikely, but look at the images:


Notice that the edges are tightly parallels. This is good, unless the top edge was cut from the bottom, a condition requiring direct examination. Then look at the perforations. They match, sort of, but not so much at the top. I did this overlay in 2018 when this image was previously posted. Would adjusting the position would result in a fit? Does it make a difference to start at one end of the row and then try the other end? I would rate the match as marginal, requiring more work to verify that the perfs are bad or that the test should be retried.
Alternatively, pass the stamp on to another expertizer.