He's(Chrono) right.
The direct damage is dealt, then the splash damage.
The splash damage is distributed depending on your range from the explosion.
If you're hit directly, you take 30 + (about) the full splash damage for being in the middle.
That being said, the radius damage cannot kill someone alone unless they have less than about 95 or so health.
Yes, the radius damage is 100, but it scales the further the player is from the damage range. Thus, the only way to do 100 damage from the radius is if the explosion happens directly inside the player's center.