How is a Buddha able to do things beyond the laws of cause-and-effect?
That sounds like it might be one of the Four Unconjecturables.


  "There are these four unconjecturables that are not to be conjectured about, that would bring madness &amp; vexation to anyone who conjectured about them. Which four?
  
  "The Buddha-range of the Buddhas[ 1 ] is an unconjecturable that is not to be conjectured about, that would bring madness &amp; vexation to anyone who conjectured about it.
  
  "The jhana-range of a person in jhana...[ 2 ]
  
  "The [precise working out of the] results of kamma...
  
  "Conjecture about [the origin, etc., of] the world is an unconjecturable that is not to be conjectured about, that would bring madness &amp; vexation to anyone who conjectured about it.
  
  "These are the four unconjecturables that are not to be conjectured about, that would bring madness &amp; vexation to anyone who conjectured about them."
  
  Notes
  
  1.
  I.e., the range of powers a Buddha develops as a result of becoming a Buddha.
  
  2.
  I.e., the range of powers that one may obtain while absorbed in jhana.


But that is an interesting question. :)