There have been bugs where playing a certain card causes the opponent to lag or disconnect.
Blizzard is usually very quick to temporarily ban those cards while they work on a fix. There are no (known) instances of this in the current card sets.
And anyway, even when this did happen, it was always due to a card that your opponent played. But in the situation you described, it was clearly your turn.
So no, this was not caused by cheaters.