injectors will put items into adjacent inventories if the inventory on the "output" side lacks room.

[fluxionary]

take the following image, supplied by another player:

if you punch the injector and the deployer's inventory is full, but the node breaker has room, it will place items into the node breaker. expected behavior: should try to place the items back in the source chest

[S-S-X]

Items can jump even further in certain situations...

[SwissalpS]

IIRC there have been jumps even if there was space in target inv. Solved it back then with tubes under the injector that fed back to source. Or smth similar. (Will have to check if that setup still exists somewhere)