The former Burnley frontman was making his first start for the Major League Soccer side in their 2-2- draw with Minnesota on Sunday after coming on as a late substitute in the 2-0 defeat to Sporting Kansas City last month.
Foster opened the scoring after 18 minutes but goals from Kelvin Yeboah (48') and Marcus Caldeira (78') threatened to spoil the afternoon before Duncan McGuire bagged a 92nd minute equaliser.
Speaking after the game, Olsen said on iDiski Times: "Yeah, this is the first time that a number nine has scored and we had two of them. So there's a big positive with this group, and we've been asking for that."
Reflecting on the goal, the coach added: "Let's be honest. It was a bit of a foul-up from them, and Lyle took advantage of it.
"But you can see the part when he does have chances; it's pretty easy for him; he understands that part.
"That's what we've seen when he is in good positions. That the ball is gonna hit the back of the net and he anticipated the error pretty well, and you know, he skirted around them and slipped it in a classy way."
Dynamo are next in action against San Diego on Thursday, 15 October.
