It's the same on PC and a major gripe I have.
I get it that the game doesn't give you credit and that you lose your consumables if you quit out of the game on your own accord. But it bugs me that that happens when you randomly DC.
Managed to wave 10.5 on Platinum the other day and the connection carked it. No credit for the kills, the revives ... nothing and all consumables lost.
It would be very nice if they could implement a mechanic that lets you keep your points and things unless it registers that you physically quit the game by hitting the quit mission button, especially with the servers being as unstable as they are.
Seriously, I play other online games as well but don't get randomly booted mid-game as often as I do on this one.
They've basically stopped working on ME3 with the last two DLCs, so there won't be a chance that this gets implemented, especially since it has been this way since launch. There already were some abuses were people deliberately disconnected hosts during an objective wave in order to get more credits, which is one of the reasons a "save items and credits"-option was never implemented
