Must agree with this we put rules in for a reason and They should stay till the AGM and then you Change them. You can not have one rule of one and another for the rest of the league. Its sad but that is why we have rules.Two points that stand out to me (both of which have been touched on)
1) The sub has bowled in another team (yours). Therefore for him / her to change teams they must resign from their current team
2) Your constitution states "no new bowlers in the last three weeks". As you only have two weeks to go the constitution would need to be changed - and as Andrew said that would require 100% of bowlers to agree to this change.
Unless both these requirements are met, in my opinion, the sub cannot bowl with the new team.
Jeanette