here's what probably happened.
the white house was looking for cover for trump's tweets about obama directing wire tapping towards trump tower. everyone knows this isn't true.
1. so they stretched the definition of wire-tapping to incorporate all surveillance.
2. they found some undirected surveillance material which showed that trump's team were in contact with the russians and others. this may or may not provide the smoking gun evidence of collusion.
3. they are making the unsubstantiated claim that this material involved illegal unmasking. pure smoke. nunes has been inconsistent in his description, which tells you there's not much there.
4. they will soon demand that this material is destroyed as going beyond the remit of the intelligence services.
5. if it provides evidence of collusion, this action will destroy the evidence.
6. nunes was given brief access to the material and told to treat it as a proof of trump's claims. he is dumb enough to play along.
7. nunes will treat future committee discussions as secret on this matter so nothing gets out.
8. trump will not admit or apologise for the wire-tapping claim.
9. nunes committee will produce nothing of value.