All of my exotic drops since February. None of them were Hawkmoon, and that's the only useful exotic I didn't have at the time. I've gotten 4 crux of Crota, 3 Gjallarhorns, 3 red death, 3 fourth horseman, 3 no land beyond, 3 truth, 3 dragon's breath, 2 Hard light, 2 thorn, 2 super good advice, 2 bad juju, 2 last word, 2 vex Mythoclasts, ice breaker, patience and time, universal remote, Suros regime, and invective all from RNG in that time alone. So, in other words, the only 3 RNG exotics that have NOT dropped for me in that time are plan C, Monte Carlo, and Hawkmoon. I've had plan C since my first raid, and got Monte Carlo in October. I have the worst good luck of any Destiny player I know.