I reproduced this behavior in Platinum.
 
The problem is not with the lasso, but with folders and how the clips are split.
 
Notice in the OP's example 2 that the split between Record 22 and Record 31 is not labeled in the folder.  This means that the folder does not recognize the split even though there is a separation line showing in the folder.  When you lasso into the folder, the folder thinks the two clips are not split and selects them both.
 
Whenever you make a split with the Split tool or "S" key, the parent folder shows the split and labels the new split with the folder name.
 
Splits made with the Comp tool in take lanes, however, do not appear to label the split in the folder track and will create the reported behavior.
 
I'm not sure if this is a defect or working as intended, but hope that this clarifies that the problem lies with the folders and the method that is used for splitting clips, not the lasso.
 
Ron

SquireBum
Notice in the OP's example 2 that the split between Record 22 and Record 31 is not labeled in the folder.  This means that the folder does not recognize the split even though there is a separation line showing in the folder.  When you lasso into the folder, the folder thinks the two clips are not split and selects them both.

That could apply in the 2nd GIF I posted, certainly. But look at the 1st GIF - it just seems to select everything. (It didn't actually select the whole track, but it did select pretty much every part of the track that was on-screen.)
 

Whenever you make a split with the Split tool or "S" key, the parent folder shows the split and labels the new split with the folder name.
 
Splits made with the Comp tool in take lanes, however, do not appear to label the split in the folder track and will create the reported behavior.

These clips weren't generated via either splitting or comping; they are all individual recordings.

That could apply in the 2nd GIF I posted, certainly. But look at the 1st GIF - it just seems to select everything. (It didn't actually select the whole track, but it did select pretty much every part of the track that was on-screen.)
 
When I look at the 1st GIF, the folder has no labels for any of the splits.  (I'm assuming the folder label is to the left in the undisplayed part of the GIF).  That's why most of the whole track is selected.  The key as to what gets selected in the folder is based on the labels.

 
These clips weren't generated via either splitting or comping; they are all individual recordings.
 
I did not test creating new recordings, so I can't comment on why the splits weren't labeled in the folder.
 
It appears that there is a defect or at least a design flaw in how the folders handle separate clips.
 
The important thing to determine is what conditions cause clips to appear in the folder as unlabeled.  Then I would create a problem report.
 
Ron

Interesting point regarding the labels; I was going on the vertical black lines as separating the different areas.
 
A quick experiment seems to show that unless every clip in the folder has a split at a given time, then it counts as one 'group' for the track folder. If any one of the tracks spans that gap, then it's counted as one contiguous block. This would seem to be a deliberate choice (so you can select the whole bunch of sort-of-contiguous data with one click) but it does still screw up the lasso operation.
 
The good news is that I can probably work around this now - I will just have to make sure all the clips start and end on measure boundaries and not bother with crossfades and the like until I am finished arranging.

Glad my explanation was clear enough to understand.
 
The confusing thing is the split bars displaying, but not the labels.
 
I tried recording 2 overlapping takes in Platinum and just like your examples, I ended up with 2 separate clips, but only 1 label in the track folder.
 
Ron

I haven't read all the posts above, but I encounter this all the time when I try to copy clips in multiple tracks to a different section. And this is EXACTLY why I was considering posting a feature request to hide ONLY track folders (leaving the tracks inside still visible).