Run this in Ruby and enjoy.

fun.rb

def easier_life
  nilmm = NilClass.instance_method(:method_missing)
  NilClass.send :define_method, :method_missing, lambda {|*whatev|}
  yield
  NilClass.send :define_method, :method_missing, nilmm
end

def broken_code
  [:only_item][10].oops.thats.very.wrong
  [:only_item][10].oops.thats.very.wrong :with, :arguments
  puts "whatever, I'm always happy"
end

easier_life do
  broken_code
end

puts 'What happens without my hack? The answer after <enter>...'

$stdin.gets
broken_code

-:3:in `block in easier_life': wrong number of arguments (1 for 0) (ArgumentError)
    from -:9:in `broken_code'
    from -:14:in `block in <main>'
    from -:4:in `easier_life'
    from -:13:in `<main>'

Oh you're right, I reproduced that with ruby 1.9.

Doing a new revision that works with 1.8 and 1.9.

... and here you go.

Thanks for the bug report!