Audio problem: After Stark escapes, he is walking in the desert, and crests the brow of a sand dune. Then, helicopters burst into view over him and you hear them for the first time. Stark was on the brow of the dune and should have heard them long before.
Audio problem: When Pepper runs out of the Stark Industries building and says "Obadiah, he's gone insane", her lips don't match with her mouth.
Audio problem: When Tony is breaking down the test run to Jarvis, a note-perfect transcript of what they say appears on the screen in the right corner. But when Jarvis says "Shall I render using proposed specifications?" the screen says "Shall I render utilizing proposed specifications?" Also the words that Tony says appear on screen before he says them. (01:06:25)
Answer: Tony, even wearing the Iron Man armour, is light enough that the shockwave of the blast throws him out of the way, so he escapes the majority of the explosion's effects. Stane, in his much heavier suit, isn't so lucky and so gets the full impact, which kills him. The flickering of the chest piece is merely a device to show that Tony is still in one piece, even if injured.
Tailkinker ★