Rulesman

In who's view was it embedded? Was it solidly embedded? The referee may well have determined it was not. Rule 23-1 no longer exists of course.

#224 means that all Open Championships will have the LR in force

The best I can do is that it wasn't on the PGA Tour hard card in 2013 The R&A include it on their hard card from this year. They didn't in 2017

It is very common on links courses in particular. The R&A include it on their hardcard from this year. They didn't in 2017

As your ball was holed it was no longer on the green. Fortunately for your buddy he did not incur a penalty. But why would you think you might have done?

That is probably one of the most common ball/marking combinations around.

If it doesn't reach the penalty area, would you be able to find it?

An attempt at criley4way's suggestion. Click to enlarge.

If you can tell me: If you are left or right handed If the tree was to the left or right of the path and how far from the edge How wide the path was and if the ball was towards the left or right of the path I'll try and do a diagram to help sort it out. But in the meantime look at the diagram in 16.1b here https://www.randa.org/en/rog/2019/rules/the-rules-of-golf/rule-16 or here http://www.usga.org/content/usga/home-page/rules/rules-2019/rules-of-golf/rules-and-interpretations.html#!ruletype=pe&section=rule&rulenum=16

16.1a(3)/1 Obstruction Interfering with Abnormal Stroke May Not Preclude Player From Taking Relief In some situations a player may have to adopt an abnormal swing, stance or direction of play in playing his or her ball to accommodate a given situation. If the abnormal stroke is not clearly unreasonable given the circumstances, the player is permitted to take free relief under Rule 16.1. For example, in the general area, a right-handed player's ball is so close to a boundary object on the left side of a hole that he or she must make a left-handed swing to play towards the hole. In making the left-handed swing, the player's stance is interfered with by an immovable obstruction. The player is allowed relief from the immovable obstruction since use of a left-handed swing is not clearly unreasonable in the circumstances. After the relief procedure for the left-handed swing is complete, the player may then use a normal right-handed swing for the next stroke. If the obstructioninterferes with the right-handed swing, the player may take relief for the right-handed swing under Rule 16.1b or play the ball as it lies.

Indeed, it is all about the 'reasonableness' or practicality of being able to make a stroke if the issue for which you are claiming relief didn't exist. You don't get free relief from anything (embedded ball, cart path, GUR etc) if you can't make a reasonable stroke because of something else preventing you from which you don't get free relief (eg being up against an OOB wall or stuck between the roots of a tree The Rule in question says Exceptions – When Relief Not Allowed for Ball Embedded in General Area: Relief under Rule 16.3b is not allowed: When interference by anything other than the ball being embedded makes the stroke clearly unreasonable (for example, when a player is unable to make a stroke because of where the ball lies in a bush). This shows that if a stroke is reasonable then relief is allowed

If your ball was sitting hard up against and OOB wall but not embedded in the ground you would find it difficult to make a reasonable stroke in any direction. If it was embedded in the ground you would therefore not be entitled to free relief. If the ball was 12" (say) from the wall then you may be able to make a stroke but not necessarily towards the hole. However in the circumstances it would be reasonable and practicable to play in a different direction. Therefore, if the ball was embedded, you would qualify for free relief for the embedded ball which may incidentally get you clear of the OOB wall.

What rule against doing so? The ball is (still) in the teeing area.

The principle applies to all free relief situations. The question to be answered is: 'If the situation from which I may take free relief (cart path, temporary water, embedded ball etc) didn't exist, would I be able to make a reasonable stroke at the ball? If the answer is no because something else interferes that you don't get free relief from (eg a tree or OOB wall), then you don't get free relief from the cart path etc.

Just to reinforce iacas's point. If a chip sideways is the reasonable shot you would have played if the ball had not been embedded and you drop in the relief area, you do not have to play a chip. If you now have a good lie and view, you may play a wood to the green if you wish.