Assuming what happened to Dubledore was real, he made two very stupid mistakes:
he didn’t count with the possibility of Voldemort having Harry and the Invisibility Cloak with him
he gloated like a cartoon villain about how he’ll trap Voldemort. Why? He needed time for the time stopping spell to charge, but why did he reveal what kind of spell it was? Also, Voldemort couldn’t have simply run away, he tried but failed. Voldemort did have extended knowledge but there was a chance he was not familiar with the spell Dumbledore was casting. So why take the unnecessary risk to warn him?
Assuming what happened to Dubledore was real, he made two very stupid mistakes:
he didn’t count with the possibility of Voldemort having Harry and the Invisibility Cloak with him
he gloated like a cartoon villain about how he’ll trap Voldemort. Why? He needed time for the time stopping spell to charge, but why did he reveal what kind of spell it was? Also, Voldemort couldn’t have simply run away, he tried but failed. Voldemort did have extended knowledge but there was a chance he was not familiar with the spell Dumbledore was casting. So why take the unnecessary risk to warn him?
I love the image of Dumbledore gloating like a cartoon villain. You’re right, of course.