Every time you replace the raw water pump impeller on that side the exhaust has to be removed; just one of those things....Thanks. Since that side is so hard to access and I've already yanked the exhaust hose, might as well replace all the hoses/clamps. Ordered new hoses and constant tension clamps.
Anyhow, coolant that is dripping from the oil pan typically is sourced around the engines accessory drive end somewhere under the heat exchanger like what @Strecker25 was saying - coolant pump seal for example. Many times a leak doesn't become apparent until the engine is hot and running.