"On the queen's level" is interesting. So it could have been a Walker?
Yes, it may have been. Harry describes the walker in Chapter 43 as not bigger, but deeper than Mab and having power "beyond anything [he] had seen, beyond measure, beyond comprehension-just plain beyond."
On the other hand, the power of the Walker could be sufficiently different that it couldn't have manipulated time at all.
Maeve does something similar after Harry rescues Molly from Arctis Tor.
I think this is what Kringle was referring to and is why I said that it was implied that a Faerie Queen that did it.