When the junkie girl blows up the house with built up gas from the stove, there is a flame showing lit in blue on one of the stove burners before she strikes the lighter; there would be no gas built up in the house... There would be no explosion.
After Ronnie shoots Michael, as Michael is lying on the ground, one can see a large mat like object on Michael's chest. This is obviously where the blood packets were placed for when Michael was shot.