In the Doctor Who episode The Time of the Doctor, Clara has her ankle grabbed by a Weeping Angel covered in snow. She is not displaced in time as is the usual result. She gets free of the Angel, no harm done.
How is this possible? It usually takes one brief touch for the Angel's power to cause you to disappear. The episodes Blink and The Angels Take Manhattan being two prime examples. In the latter, Amy was gone in an instant (I only highlight/mention this example, because like Clara, Amy was also a companion).
Keep in mind: The Angel under the snow only moved when not being observed (even though its face and eyes were covered up). And there are other angels who appear on the scene, so there is no issue with normal Quantum Locking rules. Another thing to consider is her clothes are holographic in this scene (for the Church of the Papal Mainframe), so the Angel would actually be touching her skin. Just to shut down those possible non-explanations.