I have an even worse problem of that sort - a player who reads the name of the spell, skims briefly through the description and then pretty much makes up how he thinks it would work. I really don't think he does it deliberately - he believes he's using the rules, but his bizarre versions of spells are always a lot better than the actual versions and never have negative aspects!
He actually goes one worse. He's a specialist diviner. Sometimes he want information, so he says "I'll divine it". I, naturally, ask him which spell he's casting, to which he replies "I'm a diviner, I'd just be able to do it wouldn't I? That's my speciality after all!"
The response to this is usually my players saying something like this: "A double headed tarrasque lich? I'll just kill it." To which I, naturally, ask them to roll initiative, make a few hit rolls - you know the drill. They, of course, reply "I'm a fighter, I'd just be able to do it wouldn't I? That's my speciality, after all!"
Needless to say, the diviner-playing player is unable to recongnise this satire for what it is...