St John's Wort is Poisonous?

The following article claims that St. John's Wort, Hypericum perforatum is poisonous: Ingeborg van Driel, Poisonous Plants. Coastal Grower, May 1996, pp 27-28. In a table on page 27, van Driel lists "St. John's Wort, Hypericum perforatum" as having poisonous leaves and berries.
We are concerned about this plant because we would like to use it as a ground cover in territory that is visited by pet rabbits. We have checked the Richters catalogue of course, and asked a local landscape authority, and looked in a few books, but find no other reference to Hypericum as toxic.
In general, we are not too concerned about toxic plants, as the rabbits seem to know which ones to avoid without ever having to read about them. For example, they do not touch foxglove, and in the vegetable garden, they don't nibble on sprawling tomato plants (said by some to be toxic), though they'll nibble on carrot tops that hang out of a raised bed. The rabbits don't as a rule enter the raised beds themselves, they stick to the pathways between the wooden sides of the beds and eat the weeds and escapees – sunroots, Helianthus tuberosus and such – that they find there. So they are free to roam wherever they want and eat what they want.
Nevertheless, to be on the safe side, before we plant a patch of St. Johnswort, we'd like to double check with you.

First, Hypericum perforatum does not have berries. The seed capsules vaguely resemble dried berries, but unlike some other species this species does not have berries.
The chemical constituent, hypericin, in St Johnswort can cause photodermatitis in some sensitive humans and animals. In sheep, for example, it *may* cause shedding of wool, swelling of the face, skin irritation and loss of appetite. In large doses it can cause death. Cattle, sheep, horses, goats, rats, and rabbits exhibit varying degrees of sensitivity. From the scientific literature, it appears that cattle are the most sensitive, but we could not find anything about the relative sensitivity of rabbits. But, as Christopher Hobbs writes in HerbalGram (No. 18-19, 1988-89), the plant is not a major threat to livestock because among the first symptoms of St Johnswort intoxication is loss of appetite and animals do not ingest enough to cause photodermatitis.