If you are placing a commandblock and some powered redstone in a line next to it and then destroy the redstone that is diagonal to the commandblock, the commandblock will trigger although the redstone next to the commandblock isn´t powered.
Sorry for my bad english.
MC-114311
Commandblock triggers false
Resolved
Duplicate
0
Stepping, Eric
(Unassigned)
Unconfirmed
Minecraft 1.11.2
Retrieved
During the snapshots, when the Observer still worked like initially, it showed the bugginess of Redstone Dust very well.
Here an unlisted video I recorded back then: https://www.youtube.com/watch?v=JciVOnMUcE8
Some more information about the problems with Dust, block updates it currently causes etc., can be watched here: https://www.youtube.com/watch?v=NEMARMNvDsw
Generally, I'd try to avoid using Redstone Dust currently, at least if it's about CommandBlocking/mapmaking, unless it causes no such problems like those you ran into 🙂