Article: Is it time to review 'illegal move' rule ?

Recent conflict between two players played on rapid (OTB) tournament, together with certain other doubts gave me some motive to write an article on 'Illegal move rule' which has been normally applied in rapid and blitz games. Let us go from very basics...

Illegal move (old rule)

In given position black just played Nf3+. Let us consider that white decided to move his queen to d6. If black claims 'Illegal move', because white king is under the check, white loses the game. Or f.e. if white would play something else neglecting check it would be also 'Illegal move'. 

(There is only excuse when other side would not have sufficient material to deliver checkmate (with the worst possible play by black); in such cases game would be declared as a draw.)

Fair enough. At least,  it used to be...

Illegal move (new rule)

Several years ago there was new rule introduced by FIDE related to 'Illegal move' which slowly came into the force over past years with different interpretations (depending on tournament organizer) but generally it is as follows:

1st illegal move - opposite side is granted with extra time

2nd illegal move - game is lost.

And this leaves a lot of space for various manipulations. At tournament mentioned above, there was series of moves (some forcing exchanges) done while one of opponent's king was under constant check. When his opponent finally claimed 'Illegal move', player whose king was under attack for several moves claimed that his opponent misbehaved, waiting for 'proper moment' to claim illegal move!? Rules are simple, player whose king was under attack for several moves was penalized, but was it fair from other player not to claim 'Illegal move' when he was fully aware of that for sequence of moves?

We have one similar position on diagram. White in time trouble, goes 50. e5-e6+. And notices that queen on d4 is hanging. Black missed to see check by the queen and he missed to take 50...Nxd4 but played 50...Qa6 instead. Now we have position in which black made 'Illegal move' but, as per new rule white should not claim it; referee will  put back black queen on b7, give extra time to the white player and request from black to make new move, most likely black will spot 50...Nxd4 and game is over for white (who actually followed the rules)!

After 50...Qa6 black is treatening to checkmate white king.

51. c4 Qa2+

52. Kc3 Qa5+

53. b4! Qa3+

And only now white claims 'Illegal move'! Actually for the whole sequence of last few moves game was practically illegal, impossible, black king was constantly under the check. But white waited for good moment for his claim. Once case is settled, white (who was loosing side) get extra time on his clock and opportunity to win this endgame because after 53...Nxd4 54. bxa5 Nd2+ 55. Kb4 white a pawns becomes unstoppable.

Fair or not?