The X17.0 solar flare of September 07, 2005 released high-energy neutrons, that were detected by the Solar Neutron Telescope (SNT) at Sierra Negra, Mexico. In two separate and independent studies of this solar neutron event, the energy spectra as a power law was calculated ( Sako, T., et al., 2006, ApJ, 651, 69. Watanabe, K., et al., 2006. ApJ, 636, 1135) In this paper, we show an alternative analysis, based on an improved numerical simulations of the detector using GEANT 4, and a different technique to treat the SNT data. The results indicate that the spectral index which best fits the neutron flux is nearly 3, in agreement with previous works. Based in the numerically calculated energy deposition of SNT, we confirm that neutrons were detected with at least 1GeV, which implies that the solar flare might have produced 10GeV protons; these could not be observed at Earth, as the source flare was in the east limb of the Sun.