Other than perhaps checking that /usr/bin/time was found, accepted it's parameters, was able to execute the command and completed successfully returning a sensible value in $time, nothing particularly leaps off the screen at me.
Hopefully, despite being vital, it's something non-obvious, else I'm gonna feel a bit foolish:)
Examine what is said, not who speaks.
"Efficiency is intelligent laziness." -David Dunham
"Think for yourself!" - Abigail
There is an alarm that aborts the piece of code running
in the eval block, to avoid having to wait for a program
that may take a long time to run. However, that potentially
long running program isn't killed - it just keeps on running,
till it either finds an answer, or gets killed manually
(guess what happened ;-)).