actually mina is totally right
yes, there are a couple of cases that are totally irrelevant/trivial, such as throwing cleavers from base. but let's suppose for a minute that you're not braindead and we're trying to make a point
1. what I don't understand is why mina's examples (and many of them, not just one) don't get through to you. these are basic concepts that every decent player inherently knows, and by definition most of these situations carry risks
2. yeah mina called you a name or two. we talk like this on the internet sometimes, deal with it. his delivery doesn't invalidate his argument, and instead of thinking critically about what he said, you kinda just brushed him off because he called you a bad word. and you were being a douche too
3. and on top of that, mina's a pretty skilled player in many respects, having played quite a few games with him in the past. just from reading this I am willing to bet 100 bucks that mina is not only ranked higher, but he'd crush him in any kind of [fair] competition. not saying that the guy with more skill has authority in debates, but you would much rather listen to someone who can demonstrate their claims better
here's another example to really get this point across:
you're playing blitzcrank, and you're about to catch the enemy carry off-guard with a grab. if your grab succeeds, you nuke the carry and your team wins the fight. however, you also know that the enemy alistar/amumu/whatever is nearby, and if you grab him, they get a free engage and your team loses the fight. do you grab or not?
you can't deny there is no risk, because if the tank just happens to intercept the grab, your team is fucked. it's possible you can miss and a fight doesn't happen, but that doesn't mean you can't totally screw over your team with that decision
you should probably go read up on some game theory. here's one of the most famous mathematical games:
http://en.wikipedia.org/wiki/Prisoner%27s_dilemma
you might think that it's obvious what strategy you'll pick, but there's always the chance the other person will screw you over with that same strategy. when the game and payoffs are not so clearly defined and evident in a continuous environment, of course there's going to be a lot of these hidden risks you don't realize you're taking
now get off your high horse and realize you're wrong