Cause of a burned terminal is typically corrosion or failure to tighten the terminal. I've had a few snap when tightening. I use pipe strap to hold capacitors in place when the new cap doesn't fit the old holder. I've seen capacitors walk around the compartment due to vibration, something ugly happens way too often.
“I am for doing good to the poor, but...I think the best way of doing good to the poor, is not making them easy in poverty, but leading or driving them out of it. I observed...that the more public provisions were made for the poor, the less they provided for themselves, and of course became poorer. And, on the contrary, the less was done for them, the more they did for themselves, and became richer.”
― Benjamin Franklin