Section 1033 — Involuntary Conversions
(a) General rule --
If property (as a result of its destruction in whole or in part, theft, seizure, or requisition or condemnation or threat or imminence thereof ) is compulsorily or involuntarily converted --
The threat of requisition and seizure was communicated by the NBA commissioner. For a threat to be valid, it only requires that the threat be possible (NBA can vote to strip an owner of the team) and that the threat be communicated. Added to the fact that a judge in a court of law sided with the NBA sale, this most definitely qualifies as an involuntary conversion.
Except that again Shelly Sterling was under no duress when she sold the team, and instead had the NBA assist her in finding a buyer. She had also idemnified the NBA against any legal actions by her husband or any other member of her family. So if Donald Sterlng sues the NBA and wins then she has to pay him.