I'm not aware of how the rule is written.

I would say the pre-bowl scores should count. If you don't then you open up a can of worms of someone not liking their score and trying again.

You shouldn't be able to undo a shot done in competition even if it was in a prebowl situation.

Looking at the rule book.

111e/4

We had an individual/team pre-bowl because they had to work. Later they found out that they would not have to work on that date so they appeared at the lanes to bowl.
Can the league secretary throw out their scores and allow them to bowl?

No. When an individual or team receives permission from the league and completes their prebowl, they have exhausted their eligibility for that league session.

111e/5
The league had a team pre-bowl for a specific league session. The team pre-bowled
and then, due to severe weather, the league cancelled bowling on that date and
resumed the following week. What happens to the pre-bowled scores?

If the team pre-bowled and the league session was subsequently cancelled, USBC
recommends the board meet and choose one of the following options:

Option 1: The pre-bowled scores are applied to the rescheduled league session. The team would not be permitted to rebowl that week as their scores have already been recorded and their eligibility exhausted.

Option 2: The league board null and voids the pre-bowled scores and the team is allowed to bowl the rescheduled league session.

I'd be that guy and call him out.

The prebowled scores should count and he can not bowl the current league week. I think your situation is more like the rule 111e/4 since the actual league week/session was rescheduled.  In the 111e/5 example the week/session of bowling is cancelled all together and the league schedule is resumed the following week.

He pre-bowled for a specific week and that week of bowling is still being bowled.

It's a mix of both.  The week was canceled because of weather and it was rescheduled.

Either way, if a vote is taken I'd like to think the people running the show are smart enough to NOT say anything about the score.  If he has a stellar week and people found that out and decided to disallow the pre-bowled scores...that's even worse.