Is this the moment 'fake' votes were cast in Turkey's referendum?

The referendum that is set to hand Turkish President Recept Tayyip Erdogan sweeping new powers was conducted on an 'unlevel playing field', according to international observers.
Cezar Florin Preda, of the Office for Democratic Institutions and Human Rights (ODIHR) and the Parliamentary Assembly of the Council of Europe, said: 'The two sides of the campaign did not have equal opportunities.'
'Late changes in counting procedures removed an important safeguard,' Preda added, referring to a move by the election authorities to allow voting documents without an official stamp to be tallied.
Preda's comments came as videos emerged seeming to show Erdogan officials casting fake votes on ballots, and using official stamps to authorise ballots that had not been stamped before the vote was cast - typically illegal under Turkish voting laws.
In one video a pro-Erdogan official can be seen stamping votes for 'yes' on the front of ballots, a source familiar with the Turkish voting process told Mail Online.
In another, officials can be seen adding an official stamp to ballots which have already been cast - in effect legitimising votes which could be fraudulent.
In the background of the second video, a woman can be heard saying in Turkish: 'Chairman I'm filming you now. You are stamping envelopes that came out of the box unstamped. This is a crime and you have criminal liability.'
On Monday, opposition parties complained of a number of irregularities in the voting, and were particularly incensed by an electoral board decision announced on Sunday afternoon to accept as valid ballots that did not bear the official stamp.
Electoral board head Sadi Guven defended the decision on Sunday, saying: 'There is no question of changing the rules in the middle of the game.'
On Monday he explained his rationale, saying he did not want people who had been given unstamped ballots by mistake to be 'victimised'.
Guven also denied that any of the ballot papers cast without a stamp had been fraudulent or fake.
Erdogan also spoke to supporters at Ankara airport after arriving from Istanbul, saying he was forced to fight the 'powerful nations of the world' during his referendum campaign.