What was true the day of that press conference I have no idea. I wasn't involved in the negotiations between Saban and Alabama. I have no idea whether he lied or not. My guess is the day before he was introduced as Alabama's coach is the day the deal was made. That is usually the case. If that is correct in this case, then a month before at the press conference, he was not going to Alabama.
The reason coaches answer that way all the time is because it is in no one's interest for them to say "I'm on the first bus out of town if I can get a ticket". It hurts the coach, his current employer and his potential future employer. If that makes it a lie by omission then so be it. As long as all the principals involved know what is going on among themselves I don't see it as a problem. Frankly, I don't think it is the media's or the public's business. They need not know anything.