Sudden awaking/realization
The references below give a goods indication of stages of insight leading to enlightenment. 


  ... people start laughing without control ... Is this true ?


I am not sure if any one would burst out laughing at any stages of insight. This looks like hysteria to me. 


  How is it that just the presence of a teacher is enough for such an experience ?


In a Theravada perspective, this is un true. The Dhamma is something you should realize through your efforts and not something someone can give you. Hence a mere presence of a teacher is not enough. 


  Can we say that this experiences are real Enlightenment ?


Looking at the references below this does not look like enlightenment but some other experience induced by a different kind of practice which is neither Samatha or Vipassana in the Theravada Buddhist sense.


The Map of The Journey
The 7 Stages of Insight and Purification
The Progress of Insight