You were probably just unlucky :D

But how far actually was the bridge from the island? Can you cross the water fast enough before that big robo-monster arrives? :)

I was unlucky on some island in a different way... one of the fragments was on a tiny island and there were some rocks to cross from the big island to the tiny island, but while trying to cross I accidentally fell between rocks (there was some small empty space between some rocks) and I wasn't able to jump out... so, since the water was down, the big robo-monster appeared, but it also seemed difficult for it to get to me because of the rocks :D After a while, it managed to grab me after moving to a different side.

On the next try I was more careful where I was jumping, so I didn't fall into that hole... but there were robots on top of the tiny island shooting at me while I was climbing (I had to jump on a few big rocks before getting to the top)... the big island wasn't near enough to shoot the robots from the other side and I had to climb very near them before I had them in my sight (to shoot the robots with a revolver), since they were on the top and I didn't see them from below until I climbed near the top of the tiny island (they didn't see me too before I started climbing on the last rock... the first time they shot me while I was climbing on the last rock... but after that I was more prepared and I waited for the robots with a revolver to come close to the edge before I climbed on the last rock :D).