BLU Can't learn spell

[Mholito]

Is it true (i heard in shout) that for some spells you just have to witness it and not get hit to learn?
People were saying that about self-destruct for example. I have like only 5 spells atm at Level 17 and did that Cactus A Rank (i forget it's name) and did not require 1000 needles

You don't have to get hit by any of the spells to be able to learn them. You just need to let them use it at least once before killing them.