  Recent deep photometry of the dwarf spheroidal Ursa Major II's morphology,
and spectroscopy of individual stars, have provided a number of new constraints
on its properties. With a velocity dispersion $\sim$6 km s$^{-1}$, and under
the assumption that the galaxy is virialised, the mass-to-light ratio is found
to be approaching $\sim$2000 - apparently heavily dark matter dominated. Using
N-Body simulations, we demonstrate that the observed luminosity, ellipticity,
irregular morphology, velocity gradient, and the velocity dispersion can be
well reproduced through processes associated with tidal mass loss, and in the
absence of dark matter. These results highlight the considerable uncertainty
that exists in measurements of the dark matter content of Ursa Major II. The
dynamics of the inner tidal tails, and tidal stream, causes the observed
velocity dispersion of stars to be boosted to values of $>$5 km s$^{-1}$ ($>$20
km s$^{-1}$ at times). This effect is responsible for raising the velocity
dispersion of our model to the observed values in UMaII. We test an iterative
rejection technique for removing unbound stars from samples of UMaII stars
whose positions on the sky, and line-of-sight velocities, are provided. We find
this technique is very effective at providing an accurate bound mass from this
information, and only fails when the galaxy has a bound mass less than 10$%$ of
its initial mass. However when $<2%$ mass remains bound, mass overestimation by
$>$3 orders of magnitude are seen. Additionally we find that mass measurements
are sensitive to measurement uncertainty in line-of-sight velocities.
Measurement uncertainties of 1-4 km s$^{-1}$ result in mass overestimates by a
factor of $\sim$1.3-5.7.
