Did Cruz congratulate Trump? No!
Would Trump have congratulated Cruz had the shoe been on the other foot? If you listen to what Trump said:
"They fight like hell for six months, and they're saying horrible things, the worst things you can imagine...And then one of them loses, one of them wins. And the one who loses says, 'I just want to congratulate my opponent. He is a brilliant man, he'll be a great governor or president or whatever. I'm not sure you're ever going to see me there. I don't think I'm going to lose, but if I do, I don't think you're ever going to see me again, folks. I think I'll go to Turnberry and play golf or something." - Donald Trump, April 24, 2016
So one can hardly criticize Cruz for something Trump likely wouldn't have done himself.