Dolphin’s Information displays ampersand for read-only files HTML encoded

Dolphin displays ampersand (&) as ampersand only until the file becomes read-only; then the ampersand is displayed HTML-encoded (&). The attached illustration shows the situation and should be self-explanatory.

Is there a special reason for this or should I report this to my distribution?

It is a bug, this should not be encoded in this context.

You can report it for dolphin or baloo-widgets.