I have just come back from a diving holiday with a friend of mine, whose husband had asked her "to stay below 30 metres" on all her dives. When she informed me and the DM about it, we asked if he maybe wanted to get rid of her or something. She hadn't noticed the ambiguity, although she is the native speaker, not me.
This is what is known as 'gauge thinking'. On most depth gauges (the real ones not some silly computer) shallow depths are 'lower' on the analog scale, provided they read from left to right, as most gauges do. It may be left to right in a circular pattern, but it is left to right in any case, and the deepest readings are on the right. I suppose it can be argued that is just the other way round with political thinking, but that would be a fatuous attempt at creating analogies where none exist.