I actually don't agree with this from a UX perspective. The downvote arrow is currently in a predictable position. If you move it after the timestamp, it will be in a variable position. Although, I can imagine how you could argue that the downvote arrow should not be easy to hit.
I guess in addition to raw usability perspective, how you view downvoting in general has an impact on the layout. If you want to place downvoting on equal footing with upvoting, placing them together does make some sense. If, however, you feel downvoting should be a more rare occurrence, it makes some sense to relegate downvoting to a worse position, especially in light of the seemingly frequent issues with accidental clicking.
I also find the single leading upvote to be a bit more consistent, as you are not able to downvote replies to your comments, only upvote. So in that regard, the UI would be a bit more uniform regardless of whether the comment was a reply or not.
Another straightforward possibility could be replacing the arrows with words, and making the time a link to the comment (removing "link" from trailing actions as gojomo suggested). This may result in better support for screen readers, in addition to mobile users, as well.
etcet 5 minutes ago | upvote | downvote | flag | parent
Something more like this..
note: they are supposed to be the same size.. oddly unicode down triangle is rending larger for me.