Wednesday's top scorer was first booked for simulation, which Dom described as 'harsh' but an attempt to deliberately handle the ball yielded a second caution and Forestieri was sent off.
Joe Garner then headed in the only goal of the game to earn Preston all three points.
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Dom said: "The first (booking) looked pretty harsh; the second one he can't have too many complaints.
"That changed the game and worked very much in Preston's favour. Seven minutes after the red card, Joe Garner popped up with what would be the winner.
"Preston created the better chances; Wednesday didn't have a single shot on target and in thye final third they lacked a final ball."
Watch the video for Dom's full verdict