This/That trip couldn't come/have come at a worse time

[EngLearner]

Suppose John's boss tells him that he has to go on a business trip to China next week. He's not very happy about it because he had planned to do something else instead of going to China. He thinks to himself:

Scenario #1 (five minutes after receiving the information from his boss):
This trip couldn't come at a worse time.

Scenario #2 (after boarding the plane to China):
This trip couldn't come at a worse time.

Scenario #3 (when in China):
This trip couldn't have come at a worse time.

Scenario #4 (back in the office after returning from China):
That trip couldn't have come at a worse time.

In scenarios #1 and #2, the trip hasn't started yet (the beginning of the trip is in the future at the time of speaking - hence the use of the conditional simple "couldn't come"). In scenarios #3 and #4, the trip is either underway or over (in both cases, the beginning of the trip is in the past at the time of speaking - hence the use of the conditional perfect "couldn't have come"). In scenarios #1, #2, and #3, the trip is current, so I've used "this." In scenario #4, the trip is a thing of the past, so I've used "that."

Would you agree with my reasoning? Are the bolded words and tenses used correctly in the four scenarios I've presented?

 

[jutfrank]

This trip couldn't have come at a worse time.

This could be said at any time before returning home. As soon as the boss tells John about the trip, it has already come as far as John is concerned since his alternate plans are inevitably changed.

Yes, when John is back home, he probably wouldn't refer to the trip with 'this' unless for some reason he still considers it having some kind of presence.

 

[EngLearner]

Source: "The Lawnmower Man (1992)", a movie (timestamp: 1h26m43s).

A scientist named Dr. Angelo was working on enhancing Jobe's mental capabilities (Jobe used to be intellectually disabled). At some point, his boss Timms said that he had made good progress and that the time had come to go to Washington to present his work to the people from whom they received their funding. A little later, but still before the trip, something unexpected happened with the subject (i.e., Jobe). Before going on the trip, Dr. Angelo said the following while recording his audio diary:

I was terrified of him. I'm sure he knew it. He's surpassed me alright, but his insights seem twisted. I fear for Jobe's sanity. This Washington trip couldn't come at a worse time.

Did he misspeak? Should he have said "couldn't have come"?

 

[jutfrank]

No, it's okay like that.

 

[EngLearner]

If the trip is scheduled for a certain date but hasn't started yet, the speaker going on it has a choice between "This trip couldn't come at a worse time" and "This trip couldn't have come at a worse time" (either is fine). If the trip has already happened, only the perfect form "couldn't have come" is correct.

Is my understanding correct?

 

[jutfrank]

Right.