Tim Clark calls two-shot penalty on himself for

not replacing ball in original position

FROM THE SCOTSMAN SPORTS WEBSITE
South African Tim Clark tumbled from joint third into a tie for 14th after being given a two-stroke penalty during Saturday's third round of the WGC-Bridgestone Invitational.
Clark, who briefly led by a shot after seven holes, was penalised for failing to replace his ball mark in the original position on the 16th green after removing it so playing partner Padraig Harrington could putt.The South African bogeyed the hole after three-putting, but his violation of rule 20-7 meant his one-over-par 71 was later amended to a 73, giving him a three-under total of 207.
That left him seven shots behind pacesetting Irishman Harrington, who fired a 67 in rain-softened conditions at Firestone Country Club.
"It was an unfortunate situation," Clark said. "Padraig asked me to move my ball on the last hole and it got me thinking that I may have forgotten to move it back on the 16th hole. I just had a feeling that I had not moved it back. I asked Paddy about it and he wasn't sure either.
"Our caddies thought that I had, but we wanted to make sure."Clark summoned a rules official and, following a review of the television footage, the South African was assigned a two-stroke penalty.
"The good thing about it is that I called it on myself," added Clark, who is yet to win on the PGA Tour while finishing second seven times."That sort of saved my integrity for me. That is about the only good thing that I can take out of the situation."