Leading 24-20, the troubled South Yorkshire club were at last edging towards their first Championship win of the season at Clifton Lane on Saturday.
However, Scottish winger Craig Holland crossed in the 10th minute of injury-time with the final play of a tense encounter to leave them still rooted to the bottom of the Championship table with 10 straight losses.
Key admitted he thought his side were “definitely” set to finally break their duck and said: “As far as the clock is concerned, on the board here, when it goes past 40, you get into injury-time but then it reaches 46 and 47 and he still hasn’t clocked it…?
“I just don’t understand where it all came from. Words leave me at the moment.
“Having said that we haven’t helped ourselves in the game and there were times when our discipline let us down around the offside line.
“I’ve got to bite my lip a little, but I think they have got to take a hard look at London Scottish and opportunities that could have come our way with regards to them being offside.
“I don’t really want to talk about the officials, but once again we have been hurt in the last couple of weeks.
“We are in control of our own destiny, but we also expect things to happen in the middle that are in line with what should happen.
“We got penalised three times for being offside; I think they got penalised once, if that.”
Titans secured a bonus point but it was little reward in their bid to avoid relegation,
They are now 16 points adrift of nearest rivals Scottish and Jersey, opponents they have lost to in each of the last two weeks.
Nevertheless, Key added: “The last few weeks since the Ealing game there’s a lot of things that have been going right and things we’ve been putting in place.
“I thought we saw a massive shift in performance and huge amount of character. I’m really pleased with what they did, I couldn’t have asked for much more. But it’s fair to say we’ve only got ourselves to blame; some of that indiscipline gave Scottish opportunities to kick penalties.”