$z=1.7$ fit using typical mid-infrared templates agrees with the parameters derived from the optical/near-infrared fits, we find the $z=6.5$ interpretation for JD2 substantially weakened.

The Optical/Near-infrared Photometry
------------------------------------

Given the derived redshift based on the mid-infrared photometry of the source, we critically investigate the optical/near-infrared photometry to assess potential sources of error.

The ACS $BViz$ photometric measurements are very important to the interpretation of JD2, since a significant optical detection would almost certainly rule out the $z \approx 6.5$ hypothesis. We note that @Mobasher erroneously reported that their ACS photometry was measured in an $0\farcs9$ diameter aperture, when in fact a smaller, $0\farcs48$ diameter aperture was used (M. Dickinson, private communication). A larger aperture size would lead to more conservative photometric limits, and is probably to be recommended, given the size of the galaxy as measured from the NICMOS $H$-band images (measured half-light radius $0\farcs3$, uncorrected for PSF effects, see Mobasher et al.). However, a larger aperture risks including light from three faint, neighboring galaxies located about 1 away from JD2. We have masked out regions with diameter $0\farcs9$ around those three galaxies[^1] before measuring photometry for JD2 in a $1\farcs0$ diameter circular aperture.

The ACS images were drizzled using 