This kind of thing may be expected, depending on the devices in the scenario and the signaling protocols/components that connect them. For example a PSTN call likely does not provide the gateway/CUCM with discrete events which can correspond to idle->in progress->alerting->connected - but rather as soon as the gatewy/CUCM make the call request, media is cut through and only the user knows if that media is indicating pre-ringing 'in progress' dead air/far-end ringing/in call voice/re-order tone/etc. In such a case, JTAPI can only model this as going directly from idle->connected (which is a valid transition) and/or sending several 'fake' transition events in a batch to get to the same state.
If would expect to see more defined transitions/events when making a call between a Cisco phone and another Cisco phone, though even then some direct transitions may still occur (e.g. from idle->alerting, skipping in-progress).
If none of the above seems applicable, more details about the endpoints, telephony architecture, and detailed end-to-end call flow may be helpful.
