Brolly Bug or Brolly Feature?

This didn't get any attention on the forum, so cross-posting it here:
https://www.artificialworlds.net/rabbit-escape/levels/d/97-brolly-bug-or-brolly-feature

```
r dtd 
######
# d d#
# # ##
# d d#
# # ##
# d d#
#A#A##
#M M##
#  b#O
######
:name=Brolly feature or brolly bug?
:brolly=1
:num_to_save=1
:num_rabbits=0
:solution.1=brolly&(1,0);19
```