Taysom could have thrown a softer pass with more air leading Blackmon closer to the sideline that Blackmon could have then easily run under and not lost so much momentum.
He threw a dart, and when you take it from the perspective that it was a dart, it was a very good throw. He threaded the only passing lane he had for throwing a dart. If he leads Blackmon while throwing a dart, the pass gets knocked down. It just didn't need to be a dart with how wide open Blackmon was.