Good point sport. Just who is the 'we' in : "we must now think of possible mechanical problems..."?
Always a good idea to check your facts before apportioning blame on man or machine. And it's in the rule book for accident investigation: base first options of probable cause on facts & evidence...ect
Facts - Wet runway, recently resurfaced without water run off grooving, commercial pressure to get run way open for summer Ops, possible tailwind component, prevous over run case in the past couple of weeks ect.
-my first opinion would not be to suspect the A/C at this point, and as it turns out they attempted the TOGO their way out of it,it looks like the plane was functioning and serviceable.
Bit too early to tell I'd say.