  Single photon emitters (SPEs) are often identified with a Hanbury Brown and
Twiss intensity interferometer (HBTII) consisting of a 50:50 beamsplitter and
two time-correlated single photon counters. For an SPE, the cross-correlation
of photon arrival time between the two detectors, $g^{(2)}(\tau)$, shows a
hallmark dip to zero at $\tau=0$. One common heuristic for identifying SPEs is
by measuring a system to have $g^{(2)}(0)<1/2$. Here in, we use stochastic
methods to simulate the case of a SPE observed with non-ideal detectors and
optics. We show that identification of SPEs is thwarted when the detectors have
asymmetric detection efficiency, and when detector background noise is more
than half the true SPE signal rate.
