Aircon water damage - Within wall or not?

https://preview.redd.it/by3mauxn13de1.jpg?width=4032&format=pjpg&auto=webp&s=2a839bb47157bbda566442b729ed063b138dea4c

https://preview.redd.it/0cn9yuxn13de1.jpg?width=4032&format=pjpg&auto=webp&s=9ff34b6d367acf163c98944c384fc0a15c8fb9a9

Reached under the bed to grab a pair of fancy shoes a few days ago and noticed very wet carpet and a few soaking wet stray socks & undies (and I'm not *that* old ... yet), on further investigation looks like this has been happening for a while as the skirting board has a decent amount of water damage running almost the the full length of the room.

Seems the culprit is the aircon above, at some point it looks like the coils have frozen over due to a blocked filter and it has dumped a bunch of water on the floor - the weird part is we didn't notice it happening even though we sleep under it, and there isn't a whole bunch of room for water to get dumped without it getting soaked up by bedding/pillows on the way to the floor.

My worry is that the water has been dumped within the wall and the damage is coming through from the other side. Is there any way to confirm (without cutting a hole in the wall/ripping off the skirting board) if this damage came from within the wall or from within the room?

How much am I looking at to get the skirting board replaced?