The theory under which such "stealth delegates" seem to be operating is that- while Party rules require National Convention delegates, at least on the First Ballot, to vote for the presidential contender to which they are bound and/or pledged based on the results of the votes cast by "rank-and-file" voters in their jurisdiction's Presidential Primary (thus, they cannot vote for any other presidential contender)- their abstentions would still be acceptable because these abstainers would not, in fact, be voting for any presidential contender other than (in the case of Massachusetts, already cited above) Governor Romney...
of course, this is an altogether cockeyed interpretation of the Party rules re: National Convention delegate selection, since abstaining on the First Ballot is also not voting for the presidential contender to which said "stealth delegate" is already bound/pledged (and there are sanctions, within the Party rules, to handle just such contingencies: such as replacing a National Convention delegate who refuses to vote for the presidential candidate to which he/she is bound or pledged with an alternate who will, etc. [keep in mind here that National Convention delegates actually vote in caucus prior to their votes being announced on the floor of the Convention- by the chairman of the jurisdiction's delegation- during Roll Call of the States, so it's not as if any such abstentions would, in reality, be taking place during Roll Call itself... in other words: it is not as if the Roll Call itself is one of delegates casting their votes therein as individuals (such as one might see while watching a vote in the United States Senate on C-SPAN 2)!])
