My term sheet wasn't signed so I would have understood if the entrepreneur chose the other partner.
In the case of the new vc / old vc example that wasn't me ... yes, there was a 'no shop' clause. but ...
1. those are mostly unenforceable (is a vc going to sue an entrepreneur over no shop? not likely)
2. if the team really wants to get around it they can just run out the clock. most no shops are 45-60 days.
In the end, a term sheet is really just an expression of honor and reputation.
