Tires do that sometimes. I had one go bang on a front wheel once. I thought the kids we had just passed had thrown a firecracker at me - until I couldn't steer very well. Good thing I can't (couldn't, couldn't - now I bet I could) get up much speed on that bike, or I would have had problems.

The rule I put in force after that was to change a tire ASAP when it gets a funny bump like that.

BTW, your tire seems to have failed rather quickly, mine gave me days of warning. I should have listened. You did the most you could do.