This tackle is an absolute legbreaker. It's filthy.
I'm very, very worried that there are referees on here who think that you can't award a card for PIADM. That's completely unsupported in the laws. Nothing in the laws states that a RC must be met with a DFK.
But okay, let's play that game for a moment.
One of the attributes a referee needs is knowledge of how to work the text of the LOTG to fit a situation. And for that you first need to know the LOTG. You need to know the LOTG back to front to find ways you can manipulate it (and if you don't know it back to front, why? You're getting paid to do a job).
Refereeing is also about understanding. Understanding the game, the intent behind the laws, the spirit of the game. And sometimes you may see an incident and need to think about how you can bend of manipulate the laws to get the outcome the incident really deserves. It may be that where you first think of in the laws you can't get the outcome you want, but if you understand the laws then you realise you can actually apply another passage, or argue it a different way, and get the outcome you know is needed.
Now, this incident needs a red card. Anybody on here who doesn't think it does needs to spend a bit of time thinking about what SFP means, and the role of cards in serious tackles. Because you absolutely cannot be permitting tackles like this on the field.
If, however, you mistakenly think that you can't award a RC for PIADM, then surely you'd agree that it's a tackle that deserves a RC.
So, fortunately it's very easy to apply a DFK for this. I'd argue an IFK fits best, but you could argue for a DFK. You could consider this 'attempts to kick an opponent' (given the opponent had to jump over the tackle, it's not really a stretch to apply that). OR it could come under 'tackles or challenges an opponent' 'using excessive force'.
But, there's nothing to say that a tackle cannot be careless, reckless, or uses excessive force when contact is not made with an opponent. There is nothing the laws that say you can sanction something as SFP and then give an IDFK restart.
Your conclusion wasn't supported at all from the rest of your post, but anyway - there's actually nothing in the laws to state that SFP can only be applied to a DFK offence.
This is what the LOTG says
Serious foul play
A tackle or challenge that endangers the safety of an opponent or uses excessive force or brutality must be sanctioned as serious foul play. Any player who lunges at an opponent in challenging for the ball from the front, from the side or from behind using one or both legs, with excessive force or endangers the safety of an opponent is guilty of serious foul play
Your position is not supported at all in the LOTG. However, if you're gong to stick to that position, fortunately it's very easy to find a DFK