The bug: it seems like Chronoshifters don't properly detect that a summoned creature is hostile, and will merrily haste a minion of yours that's about to kill them.
I looked through the changelog, and it doesn't seem that this has been fixed so far.
Here's what leads me to believe this is the case:
In 1.0, I was playing around with Summon. The first two times I tried it things ended badly (at least now I know to summon things out of mote-explosion range...), but the third time I got an awesomesauce razor fiend. One of the first things it killed for me was a Chronoshifter.
I was confused as this happened, because for some reason the Chronoshifter kept on hasting my fiend. I didn't mind, but I thought this was odd; I figured at the time that Chronoshifters just randomly shot out haste or slow.
However, just now I was killed by a blindingly fast Ichor Worm that was living in the same room as a Chronoshifter. I noticed that the Shifter kept on hasting it, and I realized that this was their expected behavior - they haste other enemies in order to make your life more miserable.
The only problem is that they might not be able to detect if a mob is hostile to them.