IS THIS SOMETHING...THAT...WE COULD LEARNT...?

If you are anybody talking about learning something to avoid a future diaster, then "Is this something that we could learn?". If you are a Brit talking about learning something too late, after the diasster, then "Is this something that we could have learnt? If you are a Yank or Canuk, then you must change "learnt" to "learned".

On the specific point about drink driving, the old British government Road Research Laboratory discovered years ago that we are all so inhibited that even our driving improves after a SMALL amount of alcohol. But do not try to argue this with law enforcement agents!

Learned.

You should probably also learnt some grammar.