Lost in Tom Swifties and punctuation (Question about commas)

[Tiangou]

You're shortening an independent phrase that could be a second sentence.

Where you're joining independent sentences or phrases with a conjunction -- even when the conjunction is implied -- you should use a comma.

You could write it this way:

"We finally made it to June 1st," noted Tom. Tom was dismayed.

Or this way:

"We finally made it to June 1st," noted Tom, and Tom was dismayed.

Or you could write it this way:

“We finally made it to June 1st,” noted Tom, dismayed.

Or you might construct it so that the adjective becomes a dependent part of the sentence and does not require a comma to set it off in this fashion:

“We finally made it to June 1st,” noted a dismayed Tom.