"A delegate ... shall on the first ballot at the national convention support the candidate who received the highest number of votes ... if the person is ... a candidate at the convention. If the presidential candidate ... is not on the ballot ... the ... delegates are no longer bound." [Rules of the Indiana Republican State Committee. Rule 10-2, 10-6, IC 3-8-3-11].
Delegates are not selected by the primary, so it is possible for party insiders to choose delegates who are "Trojan horse delegates," meaning they are loyal to a candidate other than the one they are bound to on the first ballot.
This is a prime GOPe opportunity to allow party apparatchiks to "steal" delegates.
Oh well, as Cruz would say, "those are the rules".
Rank and file voters need to be made aware of such things...