I think your piece is a little different from the one on the Modernist Glass site. Look at the shading and the subtlety of the colour. I've seen a few of these, with a marked differences in quality. I've seen some fairly reputable sources give a Murano attribution, but it's also clear that some were made elsewhere, or poorly copied in Murano. I've found Modernist Glass to be very reliable and open to discussion. If they're not completely sure, as in this case, they'll say so.
I think this is one of the cases where you would have the glass in hand and know precisely what to look for before you could arrive at a reasonably assured attribution.