These short inserts do indeed exist in #nCoV2019 relative to its closest sequenced relative (BetaCoV/bat/Yunnan/RaTG13/2013, seen here https://nextstrain.org/groups/blab/sars-like-cov). However, a simple BLAST of such short sequences shows match to a huge variety of organisms. No reason to conclude HIV. https://twitter.com/biorxivpreprint/status/1223245639296978951

To be clear, these observed insertions in spike protein are completely consistent with naturally occurring evolution in these viruses in bats. Spike has lots of evolutionary pressure and it mutates single bases as well as gains and loses sections across related bat viruses. 1/2

This alignment shows SARS at top, related SARS-like viruses from bats in the middle and nCoV at the bottom. Note the repeated gain and loss of RNA during natural evolution. 2/2

I've further outlined evidence against this paper in the following thread: https://twitter.com/trvrb/status/1223666856923291648