This question shouldn't really be ambiguous. Ellery has no concerns, since his relationship with Bill was over four years before, and that was not an issue for him. However, Wayne's conversation with Ellery is pretty convincing - if Bill knew he had AIDS at the time he and Wayne had their post-Gene fling, there would have been no reason for Wayne to have been using protection - and he did. If Bill really DID have AIDS then a) Gene would have been at risk and b) Wayne would not have been using condoms.