When a Scotsman pours me :

... a healthy measure of the dark muck ...

I've learned to be wary and always check whether it's a 1,2,3, or 4 finger pour. Then sip according to what my plans are the next day.

When I host similar events, I keep a tasty but far less expensive bottle (Currently McClelland) on hand. Preferably something that most folks haven't sipped before.

After the second round of the good stuff, I bring out the second tier and ask if anyone's had "this"? When they haven't, then rounds 3+ will be the second tier.

If, however, one of them doesn't like the second tier, and asks for more of the premium ... I gladly oblige - while noting who's house I'm going to have to raid the liquor cabinet at. -- Planning.