Two sources of temporary HP with same trigger

[Nikomnion]

The issue is with my Infernal pact warlock & Lost soul paragon path.

Pact boon states:
trigger: an enemy under your Warlock's Curse is reduced to 0 hit points or fewer
effect: you immediately gain temporary hp equal to your level

Lost soul's Rewards of Arcane Mystery states:
When you use an arcane power to reduce an enemy to 0 hp, you gain temporary hp equal to your Charisma or Intelligence modifier.

The case is: I use an arcane power to reduce an enemy under my Warlock's curse to 0 hp, my lvl's 20 and Cha mod's 5 (>Int mod)

I'm aware of "No stack rule" for thp, which states: If a character already has temporary hit points and receives new temporary hit points, the character keeps either the current amount or the new amount.

But in this case the gain is simultanous. So would I sum it and get 25 thp?
I'd like to make it clear rather than let the DM be generous :)
P.S.: I've seen a thing about "one lot at a time", but no proves for it.

[ThePurple]

I'm aware of "No stack rule" for thp, which states: If a character already has temporary hit points and receives new temporary hit points, the character keeps either the current amount or the new amount.

No effects in 4e actually occur simultaneously where the rules are concerned; you still have to go through them in some order. And the no stack rule isn't just a question of precedence; it's a question of source as well. Barring a specific mention, you can't stack temp hp from 2 different sources, even if they occur nominally simultaneously. If they do occur simultaneously, you simply get the largest number and the remainder are wasted.

[Nikomnion]

ok, seems right