and certainly possible. I don't recall ever hearing of a failure of this type before but it could happen. The higher temperatures might cause the hydrazine to boil or break down, increasing the pressure beyond the tank limits. According to this reference, common types of hydrazine have boiling points of around 120 degrees Celsius.

Another possibility is that the hydrazine simply expanded due to heat and ruptured the tanks. Somehow, that seems less likely based on how those tanks are constructed. The tanks have a membrane across the middle that separates the hydrazine from the pressurizing gas (often nitrogen). That membrane allows the hydrazine to flow freely without letting the gas escape. As a result, there is a void on the gas side of the membrane. The hydrazine would have to expand enough to effectively fill the void, then expand some more in order to rupture the tanks. Somehow, I just don't see this happening in less than 50 seconds unless there was very little insulation on the rocket motor. That might be possible if the insulation came loose during launch but I can't see it happening any other way. We've built satellites with internal solid rocket motors for decades and I've never heard of this type of failure before (doesn't mean it hasn't happened).