Reversing Decisions of Council?

It may be prudent depending on what the (unusual) circumstances might be.  For example, the elders might have discovered something post-council meeting that demands new action that cannot await the next meeting of council.  That is an outside the normal bounds possibility.  But in most circumstances it would be inappropriate for the elders to do this.  According to the Church Order, both elders and deacons report to and are accountable to the full council and only the council may reconsider an issue and reverse a previous decision.

I would add this.  The church is likely incorporated and it's Articles of Incorporation  likely indicate (or should if they don't) the definition of the corporation's board of directors.  The Bylaws may further elaborate on that.

If the governing documents (Articles and Bylaws) provide that all council membets constitute the board of directors, and if the council (that is, board of directord) makes a decision that is a board of directors decision (eg. whether or not to repave the parking lot), then the elders would be quite out of line to second guess that decision in contradiction to what the board of directors (that is, the entire council) decided.