Cheletropic carbene addition to ethene under Woodward-Hoffmann rules

Woodward and Hoffmann state in their seminal paper [1], that a ground-state pericyclic reaction is thermally allowed when $p+q=\textrm{odd}$, with $p=(4n)\_{antara}$ and $q = (4m+2)\_{supra}$. When I look at a cheletropic carbene addition to an ethene (see Figure, from [2]), this rule gets a bit shady for me.
  

![Cheletropic Carbene insertion](https://i.stack.imgur.com/qyZfd.png)   



Essentially, there are two ways to look at it:  

1) The HOMO is the two-electron sp2 orbital on the carbene and the LUMO the the $\pi^\*$ LUMO on the olefin.  

2) The HOMO is the $\pi$ orbital on the olefin and the LUMO the pz orbital on the carbene.
  



Case 1) results in a $p=1$ from the sp2 and $q=1$ from the $\pi^\*$, so $p+q=\textrm{even}$. The same can be verified for case 2). How can this be, since these kinds of insertion are usually thermally allowed? Even when I would add together both situations, I'd get an even number. Does the Woodward-Hoffmann system work here or am I missing something?


[1] <http://onlinelibrary.wiley.com/doi/10.1002/anie.196907811/abstract>   

[2] <http://chemistry.caltech.edu/courses/ch242/H1.pdf>


