I agree that Sci Fi is generally fairly quick, but I have had meals that took close to 90 minutes (including time waiting to be seated). So there is a chance you wouldn't finish in time to get to Indy at 1:15 pm, even if the ADR is at noon.
I also think that it's unlikely that they'll charge you the no show fee if you're a few minutes late to your reservation, but they can opt to treat you as a walk-up if needed. There is no set grace period, so it depends entirely on the CM at the podium, how busy they are (i.e., are they running behind schedule), etc.
Personally, I would keep looking for an 11:30 am ADR (for the 1:15 pm Indy show) or a 1:00 pm ADR (for the noon Indy show). I would rather have enough time between activities then spend the entire time looking at my watch worrying that I won't make the next activity.