And he was so close...

With the first two examples offered up by Vox, "religion" could be held culpable via direct motivation, while with the following examples — WWI gassings, etc. — "science" is only culpable by indirectly offering the means.

So why does science get held to a lighter standard? You go on to say...

Well, science doesn't kill people, either, or motivate them to kill.

...but you can't assert that religion does that either.

Vox is talking about culpability for mayhem. There is no functional difference if science is used as the means to commit said mayhem or if religion is used as an excuse to commit it. In other words, it is reasonable to assert that the means science provides to commit mayhem is just as likely to motivate people to use it for such as the presence and possession of religion would motivate people to commit mayhem in its name.

And you headed in the right direction, but...

And for that matter, neither does religion, except that, in Vox's Inquisitions and jihads examples, it provides the motivation. Religion may influence people to act, while science only gives them the means after being influenced.

...you backslid.

Religion doesn't influence anyone to do anything. It is an abstract concept, it has no motive will of its own. People can blame theirs or others' actions on religion, but it is just as accurate to blame the capability of science for the same actions. It comes down to how people deal with and use science and religion, not necessarily science and religion themselves.