I believe he means kill ratio. So, the number of planes shot down versus the number of V-1s shot down. If one RAF fighter was shot down for every two V-1s the ratio would be 2:1 in favor of the RAF.
So, the kill ratio of V-1s might have been higher against the RAF because it was so hard to down V-1s and doing so was hazardous. We're still talking a tiny fraction of the craft engaged, though.
Yes, according to the chart above it took down 351 aircraft. The toppling method wasnt the only one implemented, they also tried shooting them down with their guns; however, they would have to get close and often resulted in the destruction of their own aircraft as well.
This is a little bit plausible. This is how the RAF shot down V-1s: http://i.dailymail.co.uk/i/pix/2011/05/08/article-1384740-0B... (picture courtesy of the Daily Fail)
So, the kill ratio of V-1s might have been higher against the RAF because it was so hard to down V-1s and doing so was hazardous. We're still talking a tiny fraction of the craft engaged, though.