It could be, if so it has to be towed to the dealer. But before you call make sure to go into the fuse box and check all the engine fuses, then the drivers door fuse box as well has one. If a fuse is blown the key will flicker like that I've had that happen.
Also if you installed the extension cables and a fuse is blown go take a look at the cables. I had a situation where one of my cables was caught somehow near the suspension components and chaffed until it hit bare wire. Then it touched metal and shorted, causing a fuse to blow and the engine died just like yours did. That ended up with me being pushed back to my house by the police.
2007 NC, 6spd. True Red, BEGi turbocharged. Supporting mods.