If you had a network problem it is unlikely that the client would still be connected and able to issue a rollback. I have seen this message but I cannot remember what the situation is when it occurs. What Oracle wants is for the client to issue an explicit rollback statement.
There is a bug that produces this error unfortunately the OP did not include their Oracle version. The bug could be in all versions from 8 – 9.2.0.3 but is only confirmed to be in 9.2.0.3 where after Transaction Failover a commit or rollback incorrectly produces this error. According to the note a Select should produce this error. This would need to be a RAC system that uses transaction failover for this to apply: Note:2652886.8 Also TAF problem: Note:2652845.8
But it seems to me you can get this error on a distributed transaction. Oracle wants the client to issue an explicit rollback so that all parties to the distributed transaction rollback. If the application terminates due to the error then RECO will rollback the transaction. If the application issues the rollback it can then continue with additional (or retry) distributed queries.
HTH — Mark D Powell —