The the result becomes random if any piece is random.
Yes, but you need to correctly identify the random piece in order to discuss whether there are alternatives to its randomness other than intelligence. If the random piece is genetic mutation within the given biosphere, then yes, if you hypothesize that randomness is an inadequate explanation for the results, then intelligence is not the only direction one need look toward. Two directions you can look toward are external sources of biotic information (e.g., panspermia) or external forces of influence (e.g., morphic fields). Neither of those are inherently intelligent design as they're formulated, although one might hypothesize a source of intelligence to account for them (just as one might hypothesize a source of intelligence to account for natural selection alone).
You are layering unproven hypothesis atop unproven hypothesis, but that's nonetheless the answer to your question. If randomness is inadequate, intelligence is not the only potential resolution.
There's yet another solution off the top of my head: the perception of randomness is an illusion; the universe is deterministic. That doesn't require intelligent cause either.