It looks like the first tank either didn't have it's ammo doors closed, or the missile pierced the doors. The second tank worked as advertised.
I worked with an M1 Abrams commander for several years. In the first Gulf War, his unit lost an Abrams, but in a very strange way. As they came across lots of abandoned Iraqi vehicles, they began shooting them with coaxial and M2 machine gun fire. Well they shot up a truck at close range that was just loaded to the brim with anti-tank guided missiles. All the burning debris landed on and went inside one of the Abrams. American tanks don't fight buttoned up. The crew had to abandon the tank as the rocket debris and warheads burned the inside of the tank to a crisp.
In another strange twist, this Abrams commander was telling me about a large scale battle he was in. I was starting to think all this was a war story until he brought in the newspaper clippings and his awards and citation. A column of T-72s (mixed in with T-55s and other vehicles) attacked their position two days after the cease-fire in Iraq. The Iraqis were absolutely decimated. But why they attacked two days after the cease-fire is unknown.