That rumor was started by a random caller to a radio show hosted by some dude named Ben Love. Guy claimed he had friends in "high places" inside LSU. Obviously, far from a reliable source.
Also, according to your board's resident insider (VolTiger13), Ingram coming back to the team would be news to him as he has not heard anything about this nor has he seen Ingram at practice...
Here's the link to the thread about this on Tigerdroppings.
Caller on Ben Love claimed that Ingram is working out with team and back on roster.