The 49ers say no teams have contacted them, but they arent obligated to tell the truth. The broncos said they werent trading jay cutler....whoops!
I haven't seen a specific quote from crabtree saying two teams were willing to pay him, but even if he did say that, it still could be hearsay. Unless he specifically talked to a team and they said yeah sure we'd pay you 40 mil, there isn't tampering and there is zero proof that anything like that has happened to my knowledge. Goodell had a chat on NFL.com the other day and was asked about this situation and he said there was no indication of tampering.
I also would like to know why you think the niners can't trade him until after the season. This isnt baseball where you have a certain amount of time to sign him and then you are locked out. As far as I am concerned they can trade his rights at any time up until the trade deadline which isnt for another month or two.