My sourcing client just told me his attorney wants to review every contract before he signs and I did not build that into the timeline

The deal fell apart because urgency was implied but never defined, and implied terms do not hold when two people have different assumptions about what "fast" means.

Here is what I would look at across all three options you named.

The sourcing agreement is the right place to set a default response window, something like "client must accept or decline within three business days of delivery." That protects every deal you bring, not just the ones you remember to flag verbally. It also sets an expectation before the relationship has any tension in it.

The presentation template handles the deals where the default window is not enough. A probate-tied contract with a motivated seller is a different category than an open-ended off-market find. When you present a time-sensitive deal, the template should surface the deadline explicitly: "seller's hard deadline is X date, client response required by Y date to remain viable." That is not a lecture, it is information the client and their attorney both need to move at the right pace.

The front-of-engagement conversation is worth having regardless, because a written window and a labeled deadline still depend on the client understanding why the window exists. A five-minute call at the start of each engagement where you say "some of what I bring will have a hard close date of three to five days, here is what that looks like in practice" costs almost nothing and builds the shared mental model that your agreement formalizes.

You probably need all three layers, because one without the others leaves a gap.

On the seller side, being transparent about what happened, without blaming the client, often preserves more trust than silence does. Sellers who see you handle a loss cleanly sometimes become long-term referral sources.

A question for you: does your current sourcing agreement have any timeline language at all, or is it silent on response periods entirely?