Trust your partner - or use your brain

I failed to solve the following defence vs a partscore. The auction:

(1C) - 1H - (X) - pass;
(1S) - pass - (pass) - X;
(pass) - 2C - (2S) all pass

(1C) = 17+
1H = natural, not trash
(X) = any 0-4

I balanced with double, but sold out to 2S. Partner led the 8 of D, playing Scheider-Rusinow (1 or 3 higher).

_____T98
_____Q5
_____T7652
_____Q75
___________Q73
___________J8
8__________A943
___________A983

I won the ace and returned the 3 for partner to ruff. Partner shot back the 2 of C to my ace and declarer's T. How to continue?

Well, as I knew declarer had only 5 trumps (possibly 4) and another high diamond, I continued diamonds for partner to ruff without really analysing the deal. Auto-pilot. So wrong!

There wasn't really any need to analyse the deal; just follow the directions. Freddan's low club meant he didn't want another ruff. So, shift to hearts.

_______T98
_______Q5
_______T7652
_______Q75
A4____________Q73
KT9742________J8
8_____________A943
J642__________A983
_______KJ652
_______A63
_______KQJ
_______KT

Now declarer can't reach dummy to finesse in trumps without me getting the over-ruff for the setting trick. If I decided that partner may have led the wrong club and analysed the deal, this would also be the indicated shift. The fact that no other pair beat the contract either is a poor consolation (and certainly no excuse). Competing to 3C would have been even better.

Follow partner's advice. Or use your brain. Hopefully one of them steers you in the right direction...