If a player connects to a dedicated minecraft server which has a resource pack configured, then the player will join the world and only afterwards the game will load the resource pack, showing the player the Mojang splash screen.

Because the player has already joined the world at this point in time, but cannot move due to the resource pack reloading, it can happen that the player will die to a hostile mob.

The reloading of the resource packs should be done before joining the server/world.