In my opinion, Trump has taken the defeat well - I think it's clear from his initial statements that he was anticipating a possible second-place finish and was not at all panicked about being one delegate behind.
He still is taking defeat well, IMO - his personality is simply one that calls out anything that doesn't sit well with him the moment he sees it. Perhaps this is my bias, but this brutal honesty is something I find to be an endearing quality of Trump's and a reason he's likely getting my vote - he's legitimately upset that Cruz cheated, not that he lost.