There were things Miami could do to improve their offer. The reporting has stated they made their offer and drew a hard line. The reporting told us that Portland never came back to them and said this is what we want. So both sides dug their heels in and never attempted to communicate. There was definitely ego, spite, and emotion here. These people are not robots.
As it stands... what they received is something that could be beat unless they do REALLY well on a Jrue trade. Miami could have worked with OKC to change protections on their pick so they could offer 3 firsts, add in Jovic/JJJ and the first we or someone would have given for Herro... I think they fumbled the bag here and Portland decided to maybe take a little less to spite them a bit.