Regarding the overall situation, it seems the game was predetermined to be won by the blue player. All they had to do was stay at their base and wait for the opponent to inevitably break the rule. This is, to put it mildly, ridiculous.

If you're not absolutely sure that the guard is down, you shouldn't go. And if you do go, you should be prepared to admit that your risk didn't pay off.

As for whether you could have saved and asked the referee if you could pass, the referee is not allowed to tell a player whether or not the Guard of Origin (GO) has been broken in that zone. (If he had said that it's not allowed to pass, Vova would have immediately understood that the opponent hadn't broken the GO yet).