I found this happening to myself as well and I'd make a stupid mistake if I was going so fast.

Usually I was right, BUT I think it could be beneficial to make yourself slow down just a little bit. Double check up front that you've made all the inferences and set up your game boards correctly. I've found that when I spend more time up front I make fewer stupid mistakes and really force myself to be sure of my initial answers.

Overall having extra time isn't a terrible problem to have.