Basically they all knew the risk, the Sharptooth had to go, and Petrie only almost went with him trying to save Ducky by distracting the Sharptooth. It would be an heroic effort.
As for the cut footage, I first noticed it when watching Jurassic Park. My VHS is an oldie when they used to show previews of other movies coming out, and there you have the Land Before Time trailer, with Ducky luring the Sharptooth making funny faces at him, a scene that was taken out of the movie for some reason. If it wasn't for that tape I would've never met the Land Before Time, eventhough I only watched it 2 years after watching JP for the first time.
I guess we all want a special edition DVD with the uncut footage but apparently it was lost in time (or before time

).