diff --git a/ledger-tool/src/program.rs b/ledger-tool/src/program.rs
index f8c8a0fe66be84..7a5f5cc6492e6b 100644
--- a/ledger-tool/src/program.rs
+++ b/ledger-tool/src/program.rs
@@ -522,7 +522,11 @@ pub fn program(ledger_path: &Path, matches: &ArgMatches<'_>) {
     let mut loaded_programs =
         bank.new_program_cache_for_tx_batch_for_slot(bank.slot() + DELAY_VISIBILITY_SLOT_OFFSET);
     for key in cached_account_keys {
-        loaded_programs.replenish(key, bank.load_program(&key, false, bank.epoch()).unwrap());
+        loaded_programs.replenish(
+            key,
+            bank.load_program(&key, false, bank.epoch())
+                .expect("Couldn't find program account"),
+        );
         debug!("Loaded program {}", key);
     }
     invoke_context.programs_loaded_for_tx_batch = &loaded_programs;
diff --git a/program-runtime/src/loaded_programs.rs b/program-runtime/src/loaded_programs.rs
index ef269e58bcda96..419ae7330b410e 100644
--- a/program-runtime/src/loaded_programs.rs
+++ b/program-runtime/src/loaded_programs.rs
@@ -65,7 +65,9 @@ pub trait ForkGraph {
 pub enum LoadedProgramType {
     /// Tombstone for programs which currently do not pass the verifier but could if the feature set changed.
     FailedVerification(ProgramRuntimeEnvironment),
-    /// Tombstone for accounts which are not programs but might still be owned by a loader.
+    /// Tombstone for programs that were either explicitly closed or never deployed.
+    ///
+    /// It's also used for accounts belonging to program loaders, that don't actually contain program code (e.g. buffer accounts for LoaderV3 programs).
     #[default]
     Closed,
     /// Tombstone for programs which have recently been modified but the new version is not visible yet.
@@ -774,6 +776,7 @@ impl<FG: ForkGraph> ProgramCache<FG> {
             Ok(index) => {
                 let existing = slot_versions.get_mut(index).unwrap();
                 match (&existing.program, &entry.program) {
+                    // Add test for Closed => Loaded transition in same slot
                     (LoadedProgramType::Builtin(_), LoadedProgramType::Builtin(_))
                     | (LoadedProgramType::Closed, LoadedProgramType::LegacyV0(_))
                     | (LoadedProgramType::Closed, LoadedProgramType::LegacyV1(_))
diff --git a/svm/src/transaction_processor.rs b/svm/src/transaction_processor.rs
index bd3746cb553d30..d827695e159f4b 100644
--- a/svm/src/transaction_processor.rs
+++ b/svm/src/transaction_processor.rs
@@ -384,8 +384,11 @@ impl<FG: ForkGraph> TransactionBatchProcessor<FG> {
         result
     }
 
-    /// Load program with a specific pubkey from program cache, and
-    /// update the program's access slot as a side-effect.
+    /// Loads the program with the given pubkey.
+    ///
+    /// If the account doesn't exist it returns `None`. If the account does exist, it must be a program
+    /// account (belong to one of the program loaders). Returns `Some(InvalidAccountData)` if the program
+    /// account is `Closed`, contains invalid data or any of the programdata accounts are invalid.
     pub fn load_program_with_pubkey<CB: TransactionProcessingCallback>(
         &self,
         callbacks: &CB,
@@ -838,10 +841,6 @@ impl<FG: ForkGraph> TransactionBatchProcessor<FG> {
     ) -> Option<ProgramAccountLoadResult> {
         let program_account = callbacks.get_account_shared_data(pubkey)?;
 
-        debug_assert!(solana_bpf_loader_program::check_loader_id(
-            program_account.owner()
-        ));
-
         if loader_v4::check_id(program_account.owner()) {
             return Some(
                 solana_loader_v4_program::get_state(program_account.data())