No, it was all within the SUB spend period, I chatted with Amex to confirm the final date to reach the SUB spend and I was well within it. I suspect that Amex's computer system flagged one of my transactions and ruled against me, but then perhaps a human reviewed it to confirm and overruled the computer. Just a guess. That said, the points are still redeposited into my account, so I guess I shouldn't worry unless they take them away again, at which point I will contact Amex. However, these decisions are all at Amex's sole discretion (it says so in the T&Cs) and others have reported that Amex does not usually provide a specific reason for denying the Welcome Bonus, since they don't have to.