I'm a co-founder of the Center for Election Science. This was the spoiler effect. It doesn't really matter which candidate was the spoiler. It matters that the wrong candidate won. We did some analysis on this election here.
It's not a "spoiler effect"; maybe a split constituency is a better term. Spoiler implies that somebody has something, and someone else steps in and ruins it. These are all equal people running for the same office.
If anyone is a spoiler, it must be the Democratic candidate.
Your reasoning may be well-intentioned, but it is yet more 3rd-party-blaming.