This just happened to me ---- except I did it through ihg.com and managed to get it removed.
I booked a room in NYC at the Indigo there, and after I booked there were 2 confirmation numbers. They were XXXX1 and XXXX2, which I'd imagine could only be done if I was either super super quick booking or through a glitch. An example for comparison is when I booked a bunch of PB nights for my mom at the Miami property, the reservation numbers are about 150-200 numbers apart, and I just booked single nights as quickly as possible before all the blog readers snatched them all up.
Of course, I called the hotel and they though I was lying and made a mistake, but made an 'exception for a platinum member'.
Are your reservation numbers consecutive like mine were?