  We present numerical simulations of phase imprinting experiments in ultracold
trapped Fermi gases which are in good agreement with recent, independent
experimental results. Our focus is on the sequence and evolution of defects
using the fermionic time-dependent Ginzburg-Landau equation, which contains
dissipation necessary for equilibration. In contrast to other simulations we
introduce small, experimentally unavoidable symmetry breaking, particularly
that associated with thermal fluctuations and with the phase imprinting tilt
angle, and illustrate their dramatic effects. The former causes vortex rings in
confined geometries to move to the trap surface and rapidly decay into more
stable vortex lines, as appears consistent with recent experimental claims. The
latter aligns the precessing and relatively long-lived vortex filaments,
rendering them difficult to distinguish from solitons.
