does alternate version comply with SC 2.1

Hi all
I have a situation at work, where my guidance on conformance is being
questioned:

The solution offers users a timeline (Simile Timeline), which has a number
of events marked on a timeline. When one clicks with a mouse on an event,
further information is displayed about the event.
The technologies in use are HTML, CSS, JavaScript.

Currently this is only usable via a mouse click.

The developer argues that by providing an alternative version in tabular
format that this conforms (in his opinion) to SC 2.1 (*2.1* Keyboard
Accessible: *Make all* functionality available from a keyboard).

The users who are affected by this, are users who are unable to use a mouse
due to mobility issues (not sight-related), and by being forced to use the
table, they are denied the advantages offered by the timeline (e.g.:
context, comparison at a glance, etc). In my opinion they are not being
offered an equivalent but a version of lesser standard.

I need to provide a response, that will unequivocally make the point that
the alternate version is not an acceptable solution to the problem, and
that the mouse actions should be keyboard enabled.

Please help!

Kind regards
Harry