Press vs Iron... Oops

I cut out all my blocks for a quilt, using AccuQuilt, of course.   And sewed the first block together. But even though I know better, I "ironed" when putting it together.  The block is wavy and wonky.  So I did a second block, and I very carefully pressed each piece as I was constructing the block, and it turned out perfectly.  Dang, now I have to de-construct the first block and do it correctly.  Ugh.