Yesterday there were two incidents related to the so-called "mobile phone rule" that threatened to challenge the arbiters. In the first one, the Pinoy player Caesar Marquez lost the game because his phone rang out. At first, the arbiter on duty - apparently inexperienced - gave him "the benefit of doubt" and let him off! But the opponent, Bec Harris, protested and managed to have that initial ruling overturned by a second arbiter.
The second incident wasn't so clear cut. A switched off phone was accidentally activated and made an audible sound. Again, the player was given the benefit of doubt and was let off. However, the player felt quite bad about it and offered his opponent a draw despite being in a winning position (exchange up and pawn ready to Queen). The draw was accepted.
In yet another incident that I just learned about this morning, a player in the premiere section allagedly broke the mobile phone rule but no one said anything! Lucky.