Hard to know, but as discussed here some time ago its a very grey & probably contentious area.. it could be seen as advice or just a throw away comment, i wonder do pro's get told the stint of the greens , if they do then it wouldnt be advice as like yardage it is common knowledge. if they dont well then i think its open to question. i think at our level it wouldnt be much advice as our opinions on how fast any one green would be could & would differ greatly.. our ability to putt sure does any how..i would think pro's have a fair idea of what advice is & wouldnt risk it ..
"Advice" is any counsel or suggestion that could influence a player in determining his play, the choice of a club or the method of making a stroke.
So I'd say on balance no, it's not advice, it's just a general observation on something that anyone can see or work out, like it's raining, or the farways are soft, or the bunkers are deep, or the rough is thick.
It might be a bit more debateable however if he said it on the first green after he'd putted but his playing partner hadn't.
If he'd said "this green (or this putt) is fast you need to use a much shorter stroke" then I'd say that would be "advice".
Wonder when the last time a pro was pulled up for this in a comp? Has anyone on here ever actually been penalised for giving or asking for advice?
Its surely not, in essence, different to saying " its very windy today" or "the fairway grass is a bit long"
It really doesn't constitute advice as it would if you were standing over a putt and I said "you had better hit it harder as the greens are slow today"