SLING
From The Enigma 
NPL Magazine
October, 2017
LEXMAN

The explanation of the following flat comes in the form of a rebus.

That party held in Boston - funny 
     thing:
Their crime was not sedition. It was
     SLING.

HINTS:
1. The crime of the Boston Tea Party participants could be described as STEALING TEA LEAVES.
2. LEAVES is a homograph.

Answer: 

STEALING, TEA leaves = STEALING = SLING