It is not an acceptable excuse for a Canadian who is late for ice fishing. I mean it is not like you were being swept into a black hole and were rescued by aliens - and had to spend the night there rather than in your tent on Couch:
This phenomena occurs close to shore, more than 200m from any building and every year that I have skied here - so from Feb 2011.
There has been a suggestion made that it cracks here in the ice due to pressure of the water underneath expanding prior to freezing.
I have another explanation: artesian springs. And the reason for this suggestion can be seen in May.
And Tue Feb 17: