The M1 could jam in heavy mud, not an issued with the Springer.
EVERYTHING can jam in heavy mud. It's usually less of an issue with a bolt action, but they are not immune.
The semi auto's advantage over the bolt action in ammo capacity, and especially rate of aimed fire is the reason to have a semi auto in the first place.
That jungle ambush probably would have ended the same way if our side had used Tommyguns, M1 Carbines, or BARs.