Comments in script tags break syntax highlighting for most tokens inside the script tag. Some highlighting remains. I've marked the parts that are unexpectedly rendered as comments with the tilde character ~ in the related comments. In the given examples only the token call renders as expected. One would expect highlighting not to bleed into expressions at all.

html`<script>// ${123}</script>`
//  `<script>// ~~~~~~</script>`

html`<script>// ${obj.call("<hello world>")}</script>`
//  `<script>// ~~~~~~call~~~~~~~~~~~~~~~~~~</script>`