Yes, but he didn't fail, because that's not what he said. He said first electronic programmable computer. The Z1 (and successors) were electromechanical. Still impressive in their own right, true, but nothing like the electronic computers that were invented later.
Indeed, the Z1--Z4 were not much like the electronic computers built shortly later. They were in fact much more like the electronic computers built *decades* later.
Bear in mind that Eniac was a decimal machine, whereas the Z? machines were binary. ENIAC was an integer based machine, whereas the Z? machines had hardware floating point and for all except the Z1, this included denormals and exceptions. ENIAC was programmed using plugs and switches where as the Z? machines had machine code stored on tape with overlapped pipelined instruction decoding.
In almost every way, the Z? machines were much more like modern computers than ENIAC ever was.