The contract report that leaked out in Hockey Night in Canada last night and went wildfire today was brought up to Steven Stamkos during Sunday's Bolts Family Carnival event at Amalie Arena. There is something to read into the statement but it's not on Stamkos' reaction to the offer or anything like that, it's broader with rhetoric of recent weeks.
Per the Tampa Bay Times, here's a direct quote from Stamkos on the report:
"I'm not going to comment on that. [....] We haven't talked about that stuff in the media all season long and I don't know how they get a hold of stuff like that.