And their conclusion was that "if these mouse stayed frozen for 4 times longer, that means their memory was at least 4 times better". Isn't that a bit strange a

And their conclusion was that "if these mouse stayed frozen for 4 times longer, that means their memory was at least 4 times better". Isn't that a bit strange assumption? If both mice froze, means both remembered it. How can one mouse memory be better just because it acted differently after recalling something?