The reaction is exothermic and also produces H2 gas. If the metal ignites it can also ignite the H2 gas which gets spicy in a hurry, so it's reasonable for som

The reaction is exothermic and also produces H2 gas. If the metal ignites it can also ignite the H2 gas which gets spicy in a hurry, so it's reasonable for someone to interpret that as the metal exploding.