NGC is a big company and it shows. You don't really have an offer until you have a written one in hand - even if the recruiter says they're going forward with an offer and you'll see it in a few days.
The long version:
Two recruiters told me that they wanted me to interview for three NGC positions. My first two interviews went so well that one recruiter advised me to abandon the third lead. One recruiter emails me on a Thursday to tell me that they're going forward with an offer and that I should hear something early the next week.
I didn't hear anything for two weeks after I was told I would be getting an offer in a few days. I delayed accepting another offer to give NGC a chance to follow through on their promised offer. My emails/voicemails to the recruiter went unanswered.
I eventually had to give up on NGC based on the recruiters' lack of response. I accepted another offer and courteously informed all my POC at NGC that I am withdrawing my interest. Only then did that job-offering recruiter reply back to tell me that they filled the position internally.
Since I had already withdrawn, I cannot fathom any professional purpose justifying their telling me that they have selected another candidate. (you didn't really withdraw your interest, we rejected you!) That information would have been relevant and professional before I withdrew. Instead, the recruiter ignored me while I tried to give them consideration with another offer in hand.
Everybody in the interviews themselves were very nice, pleasant, and professional. My negative experience came afterwards with the recruiters and, possibly, the hiring managers.
In theory, I had three leads, two very interested hiring managers, and one offer of employment. In reality, I had bad communication, recruiters not returning my calls, a false job offer, and a spiteful response telling me that my withdrawal was moot because I would not have been hired anyway.