Wow, the argument's still going - that's great.
I wonder if we could approach this from a completely different angle, with an experiment.
Let's say we take a number of members from one species of reptile, enough to make a statistically relevant sample, and divide them into two groups. One group is provided only with the husbandry required for them to live healthy lives. The other group is provided with same and treated as "a member of the family", as Longqi puts it. Then we follow them for a lifetime.
It would be interesting to see what the differences in longevity and illness rates would be, if any. If there were, it wouldn't prove or disprove the existence of emotions; however, it could give us an idea of how reptiles respond to being treated as pets. If the illness/mortality rates are higher in "pet" animals, it would suggest regular handling is a negative experience for them. If they feel any emotions at all, these are also likely to have been negative, though not conclusively so. With that rider, we could then say a little more certainly that the species involved is not likely to experience any kind of attachment to their keeper.
Obviously, we'd need to do it with several different species, both lizards and snakes, because there's a good chance there will be variations. Personally, I'd love to see what differences would be found between social and non-social species of lizards. The addition of subgroups could finetune the experiment.
Another way to do it would be to get reptile keepers around Australia to fill out regular (voluntary) surveys. Either approach would draw out other interesting information as well.