The bug

Breaking a tripwire [attached:true] with shears replaces the block with tripwire[attached:false].
This then updates, re-attaching itself to the tripwire blocks on either side,meaning the tripwire remains.
This behavior only seems to take place when first attempting to break is with shears. After this first failed attempt, breaking the tripwire with anything seems to continually reproduce the bug.
Tripwire will break normally if first attempted with fist.

Steps to reproduce

1. Set up a tripwire strung between two tripwire hooks, like shown in the image 2018-04-29_21.39.00.png.
2. Attempt to break the tripwire with a fist. It should pop off normally.
3. Replace the tripwire, and try to break with shears, using a fast click. The tripwire will briefly change state to [attached:false], but quickly reconnects with an audible sound. Note the disarmed tag is now [disarmed:true] ,as shown in the second image.
4. Repeat trying to break the tripwire with shears or a fist, using short clicks. The attached tag flickers between true and false, but the disarmed tag remains true throughout.
5. Hold down left click to quickly break the tripwire twice in a row. This has the affect of breaking the [attatched:false] wire, and properly breaking, dropping the item.