Lion ->
<-
Goat ->
<- Lion
Cabbage ->
<-
Lion ->
<-
Goat ->
<- Lion
Cabbage ->
<-
Lion ->
Goat ->
<-
Lion ->
<- Goat
-> Cabbage
<-
-> Goat
The key is understanding the constraints and what would be an acceptable amount of bending whilst keeping to the spirit of the game.
It's never explicitly stated that you can't take things back with you so that's your "aha" loophole. Throwing all three of them across at the same time because it turns out you're a giant wouldn't be in the spirit of the game.
Lion ->
<-
Cabbage ->
<-
Goat->
"I am not allowed to leave the cabbage and lion alone together, and I am not allowed to leave the lion and goat alone together."
It says nothing about the cabbage and the goat. It would not be unreasonable to infer that you aren't allowed to leave the cabbage and the goat together, based on how goats normally behave.
Of course, that makes the puzzle unsolvable, which is why humans will catch onto it pretty fast.