If there is a problem you dog will show signs fairly quickly - most likely being sick. Perhaps best to move itoutof the dog's way if only to stop the plant being pruned further.

Sadly, yes it is.
When dogs or cats ingest insoluble calcium oxalate-containing plants, clinical signs may be seen immediately and include pawing at face (secondary to oral pain), drooling, foaming, and vomiting. Moderate to severe swelling of the lips, tongue, oral cavity, and upper airway may also be seen, making it difficult to breathe or swallow.
If your dog did not show any immediate symptoms then it may well not have eaten enough to cause problems.