"My main intent was to caution people who were saying they'd give away a large chunk of their winnings "
One of the problems with planning to share is that there aren't a lot of court opinions to offer guidance. I've thought for quite some time that a lot of winners were begging for the chance to be hit with gift taxes, but based on the number of winners who talk about sharing with family and the very few stories like the tale of the waitress I get the impression that the IRS isn't overly aggressive about pursuing people over it.
I don't have a major quarrel with the basics of estate taxes and gift taxes, but I definitely think it should be easier to share an unexpected windfall. There's a significant difference between having a bunch of money and making a gift to somebody and making a gift so that the money never even lands in your bank account (or only sits for a few days until being disbursed). If concerns about gift tax keeps people from sharing (or makes them share discreetly) then the IRS won't be collecting any gift taxes, anyway. Much like the cliché about the lottery being a tax on stupid people, gift taxes for lottery winners who share are something of a stupid tax. If you don't do at least some basic planning it's a stupid decision that could cost you if you get lucky enough to win.
"There is also another interesting point where the father is told by the GC of the lottery, NOT to sign the ticket."
I'm assuming that was based on the idea that the prize was going to be claimed by the corporation instead of an individual. I don't know how other courts would view the FL lottery position on ownership, but it suggests that simply having multiple people sign the ticket before the drawing should at least satisfy the FL lottery that those people were all owners before the ticket value became significant enough to make gift taxes matter. Perhaps that would have some weight for any ticket that has a notice saying that it's a bearer instrument.
Signing names on the ticket at any point before cashing it in certainly makes it impossible to revoke any significant sharing. You could probably still cash a ticket worth less than $600 at plenty of retailers, but if you've got to go to the lottery themselves they're going to make sure the money is paid to everyone. I expect that part of the IRS's thinking about the validity of many supposed sharing agreements is that few people who are willing to share 1/4 to 3/4 of a multi-million dollar prize would share the same portion of a $10,000 prize. The downside of that is that it may make it impossible to have the lottery pay the prize to a trust, LLC, or any entity other than the people whose names are on the ticket.