The reason he was upvoting comments as there is no competition for curation rewards.
Also I feel like he used his vote on those other comments as a voice as a response to what you did ...not to game the system.
That sounds logical but he started upvoting comments before this post and it's a pattern spammers use when they can't vote their posts as they don't think people will flag other people to remove the votes.
It sounds like pure assumptions. You are using your experience with other people to make an assumption... and assumptions are sometimes all we have to go on I understand that.
How do you KNOW this? How can you be sure of it... as I stated sometimes all we have to go on is a feeling ... but throwing someone under the bus shouldn't be just a feeling.
I once got pulled over for what a cop thought were overly tinted windows (they weren't) he then asked if I had drugs I told him i didnt and I had never even done drugs or even drank in my life. He continued to try to figure out if I had drugs and I said didnt I just tell you I dont. Then he said yeah that's what the guy said last week then we found some. He treated me like a criminal because he had interactions with criminals. That's his world experience to interact with bad people but he couldn't just treat me that way because of these things. He needed a lot more to go on