What would happen if the concentration pg h+ ions were higher inside the mitochondria than outside the mitochondria when the channel opened

In mitochondria, the metabolism of sugars is completed: the pyruvate is imported ... This allows 15 times more ATP to be made than that produced by glycolysis alone. ... (A) Most of the energy would be released as heat if hydrogen were simply burned. ... and the outside positive (as a result of the net outflow of positive ions).

The energy of proton transfer down the concentration gradient would be lost as heat and ATPs would not be formed by oxidative phosphorylation.  

Explanation:

Oxidation of NADH and FADH2 via electron transport chain generates a proton motive force with intermembrane space being positive due to a higher concentration of protons as compared to the mitochondrial matrix.

Since the inner mitochondrial membrane is impermeable to protons, protons can be transported via channel proteins only. Movement of the protons down the concentration gradient via Fo proton channels drives the ATP synthesis on the matrix side.  

According to the questions, the inside of the mitochondria has more protons. This would drive the movement of protons from the matrix to the intermembrane space via proton channels. Since the ATP synthase enzyme is present on the matrix side, the movement of protons towards the intermembrane space would not drive ATP synthesis and the energy will be lost as heat.