There's a lot to look at to determine if a player is intentionally feeding. Most of the time it's pretty evident - huge numbers of deaths with few/no kills or assists; MS-focused builds combined with Tele/Revive (rip). Sometimes, it's more complicated. Deaths/min is a good number to look at. The heat-map added to Match History helps, too.
Generally speaking, though, unless it's crazy obvious, KDA is not a strong indicator of intentional feeding by itself. Every KD you list up there is pretty reasonable to be seen in a normal game, on either side. And remember, feeding is only punishable if it's intentional.